Three-dimensional finite element analysis method and system for bearing characteristics of steel pipe piles

Abstract

The present application relates to the technical field of finite element, specifically to a steel pipe pile bearing characteristic three-dimensional finite element analysis method and system, comprising the following steps: obtaining shear strain and volume deformation sequence and mapping and homing mutation point, extracting deformation main control direction, comparing loading stage boundary offset image, tracking displacement path and response node, identifying stress misplacement section, identifying contact surface response characteristics, and dividing pile soil structure zoning map.In the present application, the mutation point distribution is extracted through the direction mapping of shear strain and volume deformation, the deformation trend main control direction is constructed, the spatial aggregation recognition ability of deformation characteristics is enhanced, the boundary offset direction is extracted through the disturbance comparison of initial and final states of loading, the response distribution extraction of interface boundary is strengthened, the settlement trend offset area is tracked through the displacement path and time sequence difference, the stress propagation abnormal section is extracted through the node misplacement in force transmission path, the zoning is divided in combination with the contact response characteristics under disturbance direction, and the structure response recognition ability under the condition of pile soil interaction is expanded.

Description

Technical Field

[0001] The present invention relates to the field of finite element technology, and in particular to a three-dimensional finite element analysis method and system for bearing characteristics of steel pipe piles. Background Art

[0002] The field of finite element technology includes modeling and simulation methods that use numerical methods to discretize continuous medium structures into a finite number of units, and solve their response characteristics under stress, deformation, instability and other conditions based on the control equations. The core content of this technical field includes geometric modeling, material constitutive relationship settings, boundary and contact condition definitions, load condition settings and iterative solution calculations. It is widely used in bridge engineering, geotechnical engineering, and underground structure engineering to simulate the stress behavior of complex structures and nonlinear materials. In engineering practice, finite element modeling is often used to study foundation-structure interaction, pile-soil interface slip behavior, structural buckling mode and bearing capacity analysis. Its operating steps include three-dimensional meshing, component parameter setting and static analysis process control.

[0003] Among them, the three-dimensional finite element analysis method for the bearing characteristics of steel pipe piles refers to a method of establishing a three-dimensional solid model of a coupled system of micro steel pipe piles, accumulation layers, and strongly weathered rock layers based on the ABAQUS platform, simulating the load response of micro steel pipe piles in medium-dense gravel and weathered rock foundations, and studying their bearing mechanism under the action of landslide thrust. This method specifically covers the conditions of changes in design parameters such as pile diameter, pile length, pile spacing, and grouting pressure. By defining the pile-soil contact surface as a finite slip surface contact, the Mohr-Coulomb constitutive model is used to treat the shear failure characteristics of the soil, and the ideal elastic-plastic model is used to simulate the yield behavior of the steel pipe. The bearing capacity simulation analysis is completed by combining static load step loading and iterative convergence strategy. The analysis objects include the shear failure of the pile-soil interface, the compression-bending buckling of the steel pipe, and the influence of the grouting reinforcement range on the deformation response of the soil.

[0004] Existing technologies lack data-driven identification methods for the dominant direction of deformation response, making it difficult to define the spatial dominant trend of the shear dilatancy effect in the anisotropic response field of the soil. The evolution of the contact boundary morphology under the influence of disturbance has not established a mapping relationship with the change of the load state, resulting in fuzzy acquisition of boundary change characteristics. The pile displacement path tracking does not combine the temporal response distribution between groups, making it difficult to define the mutual hysteresis in the settlement process. The node sequence in the stress path lacks a structural differentiation mechanism, resulting in confusion in the conduction direction under the superposition of multiple paths. The response characteristics of the pile-soil contact interface under bidirectional disturbance have not formed an interactive classification, resulting in a decrease in the accuracy of structural zoning, which overall limits the ability to accurately express the interaction mechanism of structure and soil under unstable working conditions. Summary of the Invention

[0005] In order to solve the technical problems existing in the prior art, an embodiment of the present invention provides a three-dimensional finite element analysis method for the bearing characteristics of steel pipe piles, comprising the following steps:

[0006] In order to achieve the above object, the present invention adopts the following technical solution: a three-dimensional finite element analysis method for the bearing characteristics of steel pipe piles, comprising the following steps:

[0007] S1: Obtain the shear strain trajectory and volume deformation sequence in the side slip zone of the steel pipe pile, map the shear strain and volume deformation data according to the direction, locate the shear expansion mutation point, arrange the directions according to the spatial distribution of the mutation points, and obtain the main control direction group of the shear expansion trend;

[0008] S2: Based on the calibrated direction range in the main control direction group of the shear dilatancy trend, mapping the displacement images of the interface between the grouting layer and the original soil at the initial and final stages of loading, determining the relationship between the deformation offset direction and the boundary position, and obtaining a grouting disturbance response boundary mapping diagram;

[0009] S3: Based on the mapping results in the grouting disturbance response boundary mapping map, the displacement path records are retrieved by comparing the pile body number sequence, and the response changes are compared with the hysteresis nodes to obtain the pile group settlement trend offset distribution map;

[0010] S4: based on the hysteresis response pile position numbers in the pile group settlement trend offset distribution map, tracing the continuous path of the loading reaction force, reconstructing the order of the transmission nodes, identifying the locations of the conduction sequence differences in the path, and obtaining a stress propagation dislocation section identification map;

[0011] S5: Based on the pile segment information and shear dilation direction data in the stress propagation dislocation segment identification diagram, the disturbance boundary characteristics are compared along the mutation direction, the response difference is identified, and a structural partition diagram of the pile-soil interface response state is obtained.

[0012] As a further solution of the present invention, the shear expansion trend main control direction group includes a shear strain mutation point sequence, a volume deformation mapping relationship, and a main control direction angle range; the grouting disturbance response boundary mapping diagram includes a contour offset zone, a deformation direction consistency feature, and a boundary disturbance response line; the pile group settlement trend offset distribution diagram includes a displacement path change trajectory, a response lag comparison node, and a settlement trend offset interval; the stress propagation dislocation section identification diagram includes a reaction force transmission node sequence, a stress sequence difference between loading steps, and a dislocation section number identification; the pile-soil contact surface response state structural partition diagram includes a shear expansion direction response type, a two-way action contact feature, and a structural partition identification result.

[0013] As a further embodiment of the present invention, the homing dilatancy mutation point refers to a mutation point in the shear strain trajectory and volume deformation direction sequence where the shear strain continues to increase and the volume deformation direction suddenly reverses;

[0014] The comparison of response changes and delayed nodes refers to analyzing the displacement path record time sequence of each pile top node during the loading phase, identifying the start time of the node response during the loading process, and comparing it with the response time difference between adjacent nodes and the pile body to capture the time-delayed nodes.

[0015] As a further aspect of the present invention, the reconstructing the transfer node order refers to tracing the transfer path of the reaction force between the pile segments during the loading process after identifying the delayed response pile position, and identifying the difference position in the transfer order;

[0016] The comparison of disturbance boundary characteristics along the mutation direction refers to scanning the pile-soil contact surface boundary along the direction based on the existing shear expansion mutation direction, identifying and comparing the differences in boundary direction, contour extension trend and junction information changes in the differentiated path.

[0017] As a further solution of the present invention, the specific steps of S1 are:

[0018] S101: Obtain the shear strain trajectory and volume deformation change sequence in the stratified area of ​​the steel pipe pile side slip zone, correspond each set of shear strain direction values ​​and volume deformation direction values ​​along the direction number, and analyze the change amplitude between positions with the same direction along the node sequence to obtain the corresponding section of the direction map;

[0019] S102: Based on the corresponding section of the direction mapping, identifying the relationship between the continuous increment of the shear strain value in the direction advancement path and the switching of the volume deformation direction, and locating the sequence number at the direction point where the shear strain increases and the volume deformation direction reverses, to obtain a shear dilation direction jump position group;

[0020] S103: Based on the dilatancy direction jump position group, the direction number path where the direction jump is located is screened, and the direction channel data sequence of the direction continuous trend is extracted in combination with the node sequential connection direction to obtain the dilatancy trend main control direction group.

[0021] As a further solution of the present invention, the specific steps of S2 are:

[0022] S201: Based on the calibrated direction range in the main control direction group of the shear dilatancy trend, mapping the cross-sectional structural displacement images in the interface between the grouting layer and the original soil at the initial and final stages of loading, corresponding to the directional displacement path, screening the area where the deformation direction turns at the boundary contour, and obtaining an initial direction mapping sequence;

[0023] S202: Based on the direction paths in the initial direction mapping sequence, the connected directions of the boundary points in the image are extracted, the continuous displacement paths near the boundary line are judged to correspond to the contact boundary directions, the angle change values ​​between the boundary direction paths are calculated, and the concentrated positions of the change inflection points are determined to obtain the boundary direction convergence change interval.

[0024] As a further solution of the present invention, the specific steps of S3 are:

[0025] S301: Based on the regional disturbance contour results presented in the grouting disturbance response boundary mapping diagram, the corresponding pile body number sequence is called to obtain the displacement path sequence of each pile top node in the loading stage, and the direction change process under the differentiated time step in the path is identified in the number sequence, the node path direction evolution characteristics are extracted, and the node direction change characteristics are obtained;

[0026] S302: Based on the nodes of the position point set in the node direction change feature, the displacement path difference within the loading time period is compared according to the adjacent pile body numbers, the timing difference between the node response start and transmission is identified, and the response start delay ratio between the adjacent pile bodies is calculated to obtain a delayed response ratio distribution group;

[0027] S303: Based on the delay value sequence of the numbered pile segments in the delayed response ratio distribution group, the pile body number arrangement direction is compared with the change position in the offset sequence, the path direction offset relationship is extracted in the delay change sequence, and a pile group settlement trend offset distribution map is obtained.

[0028] As a further solution of the present invention, the specific steps of S4 are:

[0029] S401: Based on the hysteresis response pile position number in the pile group settlement trend offset distribution diagram, the longitudinal reaction force data of the corresponding pile segment during the loading step are called, the arrangement process of the pile segment reaction force transmission path on the time axis within the loading step is tracked in the order of the number, and the continuity and discontinuity characteristics of the path are traced to obtain the reaction force path advancement sequence;

[0030] S402: Based on the reaction path advancement sequence, according to the time sequence of the longitudinal reaction force responses of the pile segments within the loading step, a horizontal comparison is performed on the step correspondence between the paths, and pile segment sequences with discontinuous responses are screened out to obtain a path response sequence difference interval;

[0031] S403: Based on the path response sequence difference interval, the arrangement positions of the continuous advancement segment and the discontinuous response segment in the loading direction are tracked, the deviated position areas in the response trajectory are identified along the advancement path, and the order and spatial layout of the areas in the advancement path are divided in sequence to obtain a stress propagation dislocation segment identification map.

[0032] As a further solution of the present invention, the specific steps of S5 are:

[0033] S501: Based on the pile segment information and dilatancy direction matching data in the stress propagation dislocation segment identification map, extending the contact surface state in the pile segment along the dilatancy mutation direction in a path sequence, scanning the strike change of the pile-soil contact boundary along the path direction, and arranging the contact surface response characteristics of the pile segment positions along the directional path to obtain a contact surface directional response path sequence;

[0034] S502: Based on the contact surface direction response path sequence, the extension trend of the pile soil interface boundary line is processed in the compaction disturbance direction, the difference between the paths is compared, the offset between the paths is identified according to the cross direction relationship, and the interface boundary information change characteristics are obtained;

[0035] S503: Based on the interface boundary information change characteristics, the direction arrangement of the node pile section in the contact surface direction response path sequence is called, the corresponding disturbance direction combination is sequentially embedded into the shear dilatancy mutation path, the sequence is matched synchronously, the response distribution of the pile section direction combination is marked, and the pile soil contact surface response state structure partition map is obtained.

[0036] A three-dimensional finite element analysis system for bearing characteristics of a steel pipe pile, comprising:

[0037] The shear dilatancy trend identification module obtains the shear strain trajectory and volume deformation change sequence in the steel pipe pile side slip zone, merges the nodes, correspondingly maps the shear strain and volume deformation data in the same direction, identifies the shear dilatancy mutation points in each direction, merges the mutation point distribution range, and obtains the shear dilatancy trend main control direction group.

[0038] The disturbance boundary tracking module maps and compares the cross-section structure displacement images of the grouting layer original soil interface zone in the initial and final stages of loading based on the calibrated direction range in the shear dilatancy trend main control direction group, judges the consistency of the deformation offset direction and the contact boundary, and marks the profile change position after the boundary displacement, to obtain a grouting disturbance response boundary mapping diagram.

[0039] The settlement trend analysis module compares the response lag relationship between the pile body and the adjacent pile body based on the mapping results in the grouting disturbance response boundary mapping diagram, calls the displacement path record sequence of each pile top node in the loading process, archives the response change time sequence and tracks the direction change node, and obtains a pile group settlement trend offset distribution map.

[0040] The loading path reconstruction module synchronously tracks the continuous path information of the longitudinal loading reaction force based on the lag response pile position number in the pile group settlement trend offset distribution map, reconstructs the transmission node order of the pile body reaction force between the loading steps, marks the section number according to the difference position of the stress path conduction sequence, obtains a stress propagation misplacement section identification map, and transmits to the contact response identification module.

[0041] The contact response identification module performs direction corresponding processing on the pile soil contact surface state in the differential section based on the pile section information and shear dilatation direction matching data in the stress propagation misplacement section identification map along the shear dilatation mutation direction, cross compares the contact boundary information in the compaction disturbance direction, identifies the response performance of the contact section under the action of two-way, and obtains a pile soil contact surface response state structure partition map.

[0042] Compared with the prior art, the advantages and positive effects of the present invention are:

[0043] In the present invention, the distribution of mutation points is extracted by directional mapping of shear strain and volume deformation, the main control direction of deformation trend is constructed, the spatial aggregation recognition ability of deformation characteristics is enhanced, the disturbance comparison of initial and final loading states is used to extract the boundary offset direction, the response distribution extraction of interface boundaries is strengthened, the settlement trend offset area is tracked by displacement path and time series difference, the abnormal stress propagation section is extracted by node dislocation in the force transmission path, and the contact response characteristics under the disturbance direction are combined to divide the area into zones, thereby expanding the structural response recognition ability under pile-soil interaction conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0045] Figure 1 Schematic diagram of the steps of the present invention;

[0046] Figure 2 It is a system module diagram of the present invention. DETAILED DESCRIPTION

[0047] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0048] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as an "exemplary" in the present invention should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of the word "exemplary" is intended to present concepts in a concrete manner. Furthermore, in the embodiments of the present invention, "and / or" can mean both or either of the two.

[0049] In the embodiments of the present invention, the terms "image" and "picture" may sometimes be used interchangeably. It should be noted that, when the distinction is not emphasized, the meanings they convey are the same. The terms "of," "corresponding," and "corresponding" may sometimes be used interchangeably. It should be noted that, when the distinction is not emphasized, the meanings they convey are the same.

[0050] In the embodiments of the present invention, sometimes a subscript such as W1 may be written as a non-subscript such as W1. When the difference is not emphasized, the meanings to be expressed are the same.

[0051] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0052] See also Figure 1 The embodiment of the present invention provides a three-dimensional finite element analysis method for the bearing characteristics of steel pipe piles, comprising the following steps:

[0053] S1: Obtain the shear strain trajectory and volume deformation change sequence in the stratified area of ​​the steel pipe pile side slip zone, perform the corresponding node merging operation, gradually map the shear strain and volume deformation data in the same direction, locate and identify the shear expansion mutation points in each direction, merge the distribution range of the mutation points, and obtain the main control direction group of the shear expansion trend;

[0054] S2: Based on the calibrated direction range in the main control direction group of the shear dilatancy trend, the cross-sectional structural displacement images of the undisturbed soil interface zone of the grouting layer at the initial and final stages of loading are mapped and compared to determine the consistency between the deformation offset direction and the contact boundary. The contour change position after the boundary displacement is calibrated to obtain the grouting disturbance response boundary mapping diagram.

[0055] S3: Based on the mapping results in the grouting disturbance response boundary mapping diagram, the pile number sequence is compared, the displacement path record sequence of each pile top node during the loading process is retrieved, the response change time series is archived and the direction change nodes are tracked, and the response hysteresis relationship between the pile body and the adjacent pile bodies is compared in sections to obtain the pile group settlement trend offset distribution map;

[0056] S4: Based on the hysteresis response pile position number in the pile group settlement trend offset distribution map, the continuous path information of the longitudinal loading reaction force is simultaneously tracked, the transmission node order of the pile body reaction force between loading steps is reconstructed, and the segment number is calibrated according to the difference in the stress path transmission sequence position, and the stress propagation dislocation segment identification map is obtained;

[0057] S5: Based on the pile segment information and shear dilatancy direction matching data in the stress propagation dislocation segment identification diagram, directional correspondence processing is performed on the pile-soil contact surface state in the differentiated segment along the shear dilatancy mutation direction, and the contact boundary information in the compaction disturbance direction is cross-compared to identify the response performance of the contact segment under bidirectional action, and obtain the pile-soil contact surface response state structural partition diagram.

[0058] The shear dilation trend master direction set includes a shear strain mutation point sequence, a volume deformation mapping relationship, and a master direction angle range. The grouting disturbance response boundary mapping diagram includes a profile offset zone, a deformation direction consistency feature, and a boundary disturbance response line. The pile group settlement trend offset distribution diagram includes a displacement path change trajectory, a response lag comparison node, and a settlement trend offset interval. The stress propagation misplacement section identification diagram includes a counterforce transmission node sequence, a loading step stress sequence difference, and a misplacement section number identification. The pile-soil contact surface response state structure partitioning diagram includes a shear dilation direction response type, a bidirectional action contact feature, and a structure partitioning identification result.

[0059] The specific steps of S1 are as follows:

[0060] S101: Obtain the shear strain trajectory and volume deformation change sequence in the layered area of the steel pipe pile side slip zone, correspond each group of shear strain direction value and volume deformation direction value along the direction number, analyze the change amplitude between the direction consistent positions along the node sequence, and obtain the direction mapping corresponding section;

[0061] First, multiple hierarchical regions are divided in the slip zone. The shear strain direction value and the volume deformation direction value in each hierarchy are extracted. For example, in the second layer region, the shear strain direction of a point at loading step 3 is 78°, and the volume deformation direction is 82°. This group of data forms a pair of direction values. Extract the same type of direction pair on all point positions and number them according to the direction angle. The starting angle 0° is set as the reference. Each 30° of the direction angle is divided into a segment and numbered. In this way, each pair of direction values can be assigned a number. After completing the direction pair numbering, the number change sequence at the corresponding loading step is extracted along the sequence of points on the slip path. For example, the number of the third step on a certain path is 4, and the number of the fourth step is 5, indicating that the direction has an increasing trend. Then, the number change amplitude between each adjacent two steps is processed. The difference between the shear strain direction number and the volume deformation direction number is taken and compared with its absolute value. If the difference between the two directions is not more than the threshold value ±12°, it is determined that the current position meets the direction consistency standard. For example, the direction difference of three consecutive points on the path is 8°, 9°, and 10°, respectively, which continuously meets the condition. If a point exceeds the threshold value, the direction consistency is interrupted, and the detection needs to be restarted. This operation processes the direction change situation segment by segment for the whole path. The segments that continuously maintain a relatively close direction are attributed, thereby forming a direction consistent region set. Through the above operation, the attribution and correlation of the direction data can be completed based on the direction change of each measuring point in the loading process without relying on a specific structure assumption. Finally, the direction mapping corresponding section is obtained.

[0062] S102: Based on the corresponding section of the direction mapping, the relationship between the continuous increment of the shear strain value in the direction advancement path and the switching of the volume deformation direction is identified, and the sequence number is located at the direction point where the shear strain increases and the volume deformation direction reverses, to obtain the shear dilation direction jump position group;

[0063] First, the shear strain value and volume deformation direction value at each node position in the slip path are synchronously called, the shear strain value is extracted in the order of the path, and arranged in sequence according to the loading steps. For example, the shear strain values ​​from the 1st to the 5th step in a certain path are 0.002, 0.003, 0.004, 0.006, and 0.009, then the shear strain value of the path segment is judged to be a continuous incremental trend. At the same time, the volume deformation direction value sequence under the corresponding loading step is extracted along the same path. If the direction values ​​of the first 3 steps are 45°, 50°, and 53°, and the 4th step is 182°, it can be judged that the volume deformation direction at the 4th step has a direction reversal of about 180°. In this way, all loading steps are retrieved in the order of the path, and the shear strain value is compared point by point to see if it keeps increasing continuously. If the shear strain value is not less than 0.001 difference between three consecutive steps, , it is judged as incremental continuity. At the same time, if the direction of the volume deformation direction value switches and exceeds 165° in the three steps, it is judged that the direction reversal occurs at this point. Taking the above path as an example, the shear strain value increases from 0.004 to 0.006 between the 3rd and 4th steps, and the volume deformation direction changes from 53° to 182°, which meets the dual conditions of amplification and reversal. The loading point of the 4th step is positioned as the direction jump point. Subsequently, the above dual judgment operation is performed on all points in the slip band path, and the path points that meet the conditions are located one by one. Their position sequence is used as a number and included in the jump sequence. The above method is used to act on the corresponding sections of all direction mappings respectively, and the comparison processing between the shear strain value increase and the volume deformation direction reversal is promoted section by section to achieve accurate extraction of the jump path, and finally obtain the shear dilation direction jump position group.

[0064] S103: Based on the dilatancy direction jump position group, the direction number path where the direction jump is located is screened, and combined with the node sequential connection direction, the direction channel data sequence of the direction continuous trend is extracted to obtain the dilatancy trend main control direction group;

[0065] First, read the path direction number information corresponding to each jump position. The screening condition is that there is at least one position point in the path where the shear strain value continuously increases and the volume deformation direction is reversed. As the direction jump criterion, the path direction number data that meets the conditions is extracted. For example, the jump point sequence number in the path number P12 is the 4th point, and its direction number is 73°, then the path P12 is recorded as the candidate path, and the remaining path number sets are operated in turn to obtain all path number sets that meet the jump conditions. Secondly, according to the numbering sequence of the nodes in the shear strain trajectory and the volume deformation trend, the direction trends of the direction numbers in the filtered paths are arranged in the order before and after the jump points. For example, the direction sequence before the jump point in the P12 path is 69°, 71°, and 73°, and the subsequent ones are 75° and 77°, then it is judged that The direction channel is determined to show a continuous directional increasing trend, and its numbering sequence is used as the connection sequence of the direction channels. Subsequently, the direction values ​​in all the direction number sequence sets are summarized with the path number as the index, and the direction number channels that exist continuously in multiple path directions and have the same node order are extracted. If there are multiple direction channels that contain the direction number sequence from 71° to 81° and the node numbers are consistent, then this direction segment is regarded as part of the continuous direction channel. Finally, each group of continuous trend direction segments is extracted from the path direction set, and the number of overlaps in all paths is recorded. If a direction segment appears in no less than three paths, it is determined to be the concentrated direction of the shear dilatancy trend. All direction segments that meet the conditions are included in the channel set, and finally the shear dilatancy trend main control direction group is obtained.

[0066] The specific steps of S2 are:

[0067] S201: Based on the calibrated direction range in the main control direction group of the dilatancy trend, the displacement images of the cross-section structure in the interface between the grouting layer and the original soil at the initial and final stages of loading are mapped. The corresponding direction displacement path is used to screen the area where the deformation direction turns at the boundary contour to obtain the initial direction mapping sequence;

[0068] First, the channel path number corresponding to each direction number is extracted from the acquired shear dilatancy main control direction, and the two-dimensional displacement images of the corresponding cross-section in the interface zone between the grouting layer and the original soil at the initial and final stages of loading are obtained. The displacement images are obtained by collecting the displacement vector information of the monitoring points in the plane direction during the loading process. Then, according to the path index of each numbered direction in the shear dilatancy main control direction, the corresponding starting and ending points of the path in the image are extracted, and the directional displacement path segments are drawn in the order of the path numbers. Each path segment consists of a set of displacement vector directions between adjacent nodes. Then, the angle change between the two adjacent directional vectors is detected node by node on each path segment, and it is determined whether the angle direction has a jump behavior from the positive direction of the original trend to the reverse direction. If the jump angle is greater than the preset inflection criterion angle threshold W (set W = 35°), the jump point is considered to be a deformation direction turning point. For example, in the path numbered D102, the direction from node A to node B is 70°, and the direction from node B to node C is 115°. The angle detected at node B is 45°, which is greater than the threshold θt. The point is determined to be a direction turning point, and the boundary value of the corresponding boundary contour area is extracted in the image. Then, the turning point identification step is performed path by path, and a set of direction jump points is obtained in each path direction. Finally, the points with turning behaviors in all paths are merged in sequence according to the direction number, and the turning point path segments under the direction consistency trend are connected and numbered and encoded to finally obtain the initial direction mapping sequence.

[0069] S202: Based on the direction paths in the initial direction mapping sequence, the connected directions of the boundary points in the image are extracted, the correspondence between the continuous displacement paths near the boundary line and the contact boundary directions is determined, the angle change between the boundary direction paths is calculated, and the concentrated position of the change inflection points is determined to obtain the boundary direction convergence change interval;

[0070] The calculation formula for the angle change between boundary direction paths is as follows:

[0071] ;

[0072] in, Representative The angle change between the segment boundary direction paths, Representatives participated in the calculation The angle between each path segment and the contact boundary direction, Represents the average value of the angles of all path segments involved in the calculation, Representative The translation displacement value of the boundary point corresponding to the path segment, Representative The horizontal projection length of the path segment, Represents the total number of path segments involved in the calculation of angles and displacements, Representative The instantaneous displacement velocity of the boundary point of each path segment, represents the time interval between image frames, Representative The path length of each path segment;

[0073] Assumption: (Based on paragraph as an example):

[0074] ;

[0075] ;

[0076] ;

[0077] ;

[0078] ;

[0079] ;

[0080] Angles and displacements involved in averaging:

[0081] - ;

[0082] The calculation process is as follows:

[0083] The composite term of bias and normalized shift is:

[0084] ;

[0085] ;

[0086] ;

[0087] ;

[0088] Speed ​​impact items:

[0089] ;

[0090] result:

[0091] ;

[0092] Interpretation of results and numerical significance:

[0093] The value indicates the current path segment The directional change trend under the angle fluctuation and normalized velocity disturbance terms is 3.4061. If the discrimination threshold is 3.0, the path segment is identified as a potential disturbance inflection point;

[0094] Formula innovation description:

[0095] The benefit of the formula lies in that it constructs the basic quantity of the disturbance direction offset trend through the composite calculation of the angle fluctuation value and the normalized translation amplitude of the path segment. Without relying on the comparison of adjacent segments, it introduces a dynamic response factor through the ratio of the single path velocity to the displacement time, independently evaluates the strength of the disturbance trend in the local path segment, enhances the matching ability of the boundary change feature extraction in discontinuous paths, avoids the trend misjudgment problem under the condition of inconsistent direction, and improves the stable recognition accuracy of the disturbance concentration area of ​​the boundary segment.

[0096] S203: Based on the regional path in the boundary direction convergence change interval, identify the directional connected segments of the boundary region image before and after loading, check the difference in the continuous direction of the contours in adjacent segments, draw the direction-shifted area at the contact boundary position, and obtain the grouting disturbance response boundary mapping diagram;

[0097] First, according to the boundary segment range defined in the path, the corresponding boundary area images are obtained for the pre-loading stage and the post-loading stage respectively, and the directional feature pattern in each time period is extracted. The directional feature pattern is obtained by reading the displacement vector direction of each node in the boundary area. Each group of nodes is connected in sequence along the path to form a continuous set of connected segments. Subsequently, the direction of the connected segments is detected along the path direction in the pre-loading image, and the direction values ​​of the starting point and the end point of the segment are classified by angle. In this way, it is identified whether there is a directional offset between two adjacent connected segments. The specific judgment method is to take the vector angle difference at the same position segment in the pre-loading and post-loading images. If the angle difference between the two exceeds the specified offset identification angle δθ, for example, if A is set to 20°, the adjacent segment is considered to have a directional offset. This process is repeated in each regional path. When a connected segment and its adjacent segment satisfy the direction angle difference exceeding the threshold before and after loading, the segment is considered to be an offset position area. At this time, the boundary area variation layer is drawn based on the contour of the corresponding position of the segment in the image. The layer can use the contour filling method to fill the boundary offset deformation value of each direction segment in the figure, and use the image coordinate index to mark each variation point. For example, in path number R15, the 3rd to 6th nodes form a connected segment with a direction of 95° before loading, which becomes 125° after loading, with an angle of 30°, exceeding the identification value A, and is determined to be an offset segment. The positions of the 3rd to 6th nodes are plotted on the image. All positions that meet the conditions are plotted in sequence along the path, and finally the grouting disturbance response boundary mapping map is obtained.

[0098] The specific steps of S3 are:

[0099] S301: Based on the regional disturbance contour results presented in the grouting disturbance response boundary mapping diagram, the corresponding pile body number sequence is called to obtain the displacement path sequence of each pile top node in the loading stage, and the direction change process under the differentiated time steps in the path is identified in the number sequence, the node path direction evolution characteristics are extracted, and the node direction change characteristics are obtained;

[0100] First, according to the distribution pattern of the regional boundary change zone in the figure, the pile body number sequence involved in the corresponding area is extracted, and the pile top node number list corresponding to the number sequence is called in actual operation. Then, the time step of each node in the whole loading stage is uniformly divided. For example, each stage is divided into 10 time step intervals, and the displacement path records of each time node are divided accordingly. For each pile top node, its displacement vector changes are arranged in sequence from the first time step to the tenth time step, and the displacement direction change values ​​of the two adjacent time steps are obtained in turn. This value can be calculated by connecting the direction difference of the displacement vector of the starting point and the end point. Subsequently, the direction difference values ​​of each segment in the time series are arranged to determine the position point where the direction is continuous or sudden. For example, the pile top node numbered P021 If a point is found, its direction change value continues to increase between the 3rd and 6th time steps, and a direction reversal occurs in the 7th time step, then the direction path of this node is determined to be in an inflection point state. The same processing is continued for the nodes in the entire numbered list. At the same time, the behavior sections of the angle continuously increasing, decreasing or suddenly turning in the path change are extracted, and their path states are reset, thereby forming a full description of the direction change of each pile top node during the loading process. On this basis, the direction sequence change law of each node is mapped into three types of state paths, one is the direction continuous deviation path, one is the sudden turn and recovery path, and the other is the stable direction path. Finally, the angle change sequence extracted from these path states is used as a quantitative feature to describe the evolution of the direction trend, and the node direction change feature is obtained.

[0101] S302: Based on the nodes of the position point set in the node direction change feature, the displacement path difference within the loading time period is compared according to the adjacent pile body numbers, the timing difference between the node response start and transmission is identified, and the response start delay ratio between the adjacent pile bodies is calculated to obtain the delayed response ratio distribution group;

[0102] The calculation formula for the response initial delay ratio between adjacent piles is:

[0103] ;

[0104] in: Represents adjacent pile nodes and The response start delay ratio between Representatives in the number and The startup time of the node with the latest response startup time among the pile nodes, Representative number is and The startup time of the node with the earliest response startup time among the pile nodes, Represents a connection node and The rate of change of contact surface direction on the path, Represents a connection node and The difference in energy consumption between the perturbation path and the reference path;

[0105] Monitor the node and , the response start times are 5.2 seconds and 3.0 seconds respectively,

[0106] but: , ;

[0107] The angle change gradient is measured as: ;

[0108] Disturbance force and displacement: , ;

[0109] Reference status: , ;

[0110] Calculate the perturbation energy difference:

[0111] ;

[0112] Calculate the square of the response start time difference:

[0113] ;

[0114] Substituting into the formula:

[0115] ;

[0116] Interpretation of results and numerical significance:

[0117] The calculated result is 5.77, which means and The time delay differences between nodes at the response starting point under load disturbance conditions are adjusted for directional disturbance and energy consumption, which can be used for node delay sequence analysis and response misalignment segment derivation.

[0118] Formula innovation description:

[0119] The benefits of the formula are that it improves the component sensitivity of time delay in the results by introducing the square difference of response time, strengthens the weight control of path geometric perturbation on response delay through the directional perturbation gradient, and filters out geological fluctuations or local loading anomalies through the square root normalization operation of the perturbation energy consumption difference.

[0120] S303: Based on the delay value sequence of the numbered pile segments in the hysteresis response ratio distribution group, the pile body number arrangement direction is compared with the change position in the offset sequence, and the path direction offset relationship is extracted in the delay change sequence to obtain the pile group settlement trend offset distribution map;

[0121] First, based on the pile segment number, the response delay value of each numbered pile segment during the loading process is obtained. This value is obtained by the time difference between the initial reaction moment of the displacement of the pile top node and the initial loading moment. Then, the delay sequence of all pile segments is sorted according to the numbering order, and the positions are matched one by one with the actual arrangement direction of the pile body to form the pile segment arrangement path in the loading direction. The delay value sequence changes are compared according to the node order on the path, and the turning point of the rising or falling trend of the delay value is identified. For example, on a certain path, the delay value between pile segments P103 and P106 shows an upward trend, and the delay value starts to decrease from P107. This turning point is the offset trend turning point, and similar change sections on all paths are further identified. The corresponding offset direction is recorded in the path direction offset corresponding list. Then, based on the direction offset relationship and the spatial arrangement relationship of the pile body, the planar projection distribution of the settlement trend is depicted according to the mapping results between the offset directions of each path. During the operation, a set of delay values ​​on multiple directional channel paths is introduced, and they are compared respectively. The difference in delay value changes is spatially correlated. For example, if the delay value offset degree between the northwest direction path and the south direction path exceeds the set change limit, it is marked as a trend separation path segment. Finally, all path offset relationships are integrated and drawn on a two-dimensional plane, and the corresponding pile segment numbers and direction directions are marked to obtain a settlement trend offset distribution map of the pile group.

[0122] The specific steps of S4 are:

[0123] S401: Based on the lag response pile position number in the pile group settlement trend offset distribution diagram, the longitudinal reaction force data of the corresponding pile segment during the loading step is called, the arrangement process of the pile segment reaction force transmission path on the time axis within the loading step is tracked in the order of the number, and the continuity and discontinuity characteristics of the path are traced to obtain the reaction force path advancement sequence;

[0124] First, according to the number list shown in the figure, extract the pile segment information corresponding to each number, and locate the data record sequence of each numbered pile segment during the entire loading process. Then, call the longitudinal reaction force value of the pile segment under each loading condition during the entire loading process, and organize it into a time series reaction force list in the order of loading steps. Then, arrange the reaction force time series of each pile segment in the order of numbers, sort out the transmission relationship of the reaction force changes between each pile segment at the same time step, and judge the response order of the reaction force value changes in adjacent pile segments. In this way, the time continuity mode of the loading transfer path is inferred, and the location where the response interruption or stage response change occurs on the path is further identified. In this process, a simple The judgment criteria are as follows: if the reaction force of a pile segment does not change within three consecutive loading steps, while the reaction force of its adjacent pile segment increases continuously, it is considered that the pile segment has interrupted the transmission of the action on the path. The starting and ending loading steps of the segment and the numbers of the adjacent pile segments are recorded, and based on this, an image of the advancement process of the continuous reaction force response in the loading path is drawn. At the same time, an example is introduced for verification. For example, a complete reaction force continuous sequence is formed between pile segments P203 and P206, and three steps of invalid response appear at P207. Then P203 to P206 are delineated as a continuous reaction force advancement path. According to this method, identification is carried out in the entire numbered section, and a map is drawn to represent all valid path connections and interruption nodes to obtain the reaction force path advancement sequence.

[0125] S402: Based on the reaction path advancement sequence, according to the time sequence of the longitudinal reaction force response of the pile segments within the loading step, the step correspondence between the paths is horizontally compared, and the pile segment sequences with discontinuous responses are screened out to obtain the path response sequence difference interval;

[0126] The time stamps of the longitudinal reaction force responses of all pile segments in each loading step are called, and the loading response sequences of all pile segments in different paths are presented in parallel. The horizontal comparison operation of the response process between paths is carried out based on the time axis. In the comparison process, the reaction force increment response time of adjacent pile segments in each path needs to be extracted, and the response time set of the reaction force mutation corresponding to the same loading step between paths is established. The relative position difference on the time axis is judged, and 10s is set as the step response difference limit. If the response time difference of two paths exceeds this limit under the same loading step, it will be judged as a response step difference sample. At the same time, the comparison is carried out in combination with the pile segment number direction. Screening is performed to find pile segments with no continuous increase in response time in the path samples in the same direction, and these segments are listed as response discontinuous segments. Then, the position, loading step number, response time and other information of these pile segments in the path sequence are transferred to a new arrangement sequence, and a deviation trend trajectory line diagram is drawn within the time step. For example, the response intervals of pile segments numbered P108, P111, and P114 during loading steps L4 to L7 are 8s, 15s, and 21s, respectively. Among them, P111 and P114 have exceeded the step response difference limit and are recorded and listed as response discontinuous segments, thus obtaining the path response sequence difference interval.

[0127] S403: Based on the path response sequence difference interval, the arrangement positions of the continuous advancement segment and the discontinuous response segment in the loading direction are tracked, and the deviation position areas in the response trajectory are identified along the advancement path. The order and spatial layout of the areas in the advancement path are sequentially divided to obtain a stress propagation misalignment segment identification map;

[0128] First, trajectory tracking operations are carried out on all pile segments in the loading direction path in chronological order, and the reaction force response moments of each pile segment on each path during the loading process are called. The time labels are sorted along the path direction, and the positions where the response moments do not continuously increase in the path are screened as potential deviation segments. For each path, the pile segment numbers and their response time distribution curves of the continuous advancement segments are obtained, and the positions of the discontinuous response segments are inserted on the curve to identify the interruptions of the response time in the path. For example, in path A, numbers P204, P205, and P206 show continuous responses in loading steps L5, L6, and L7, while the response time of P207 is delayed to L9. It can be determined that P207 is a discontinuous response segment. Subsequently, the positional relationship between the front and rear pile segments is mapped one by one along the path direction and plotted on the path direction diagram. The correlation curve between the actual spatial position and number of each pile segment is drawn. For each pile segment identified as a response interruption, the spatial interval with its preceding and following segments is drawn on the graph and the difference in the direction of its displacement vector is calculated. In this way, the displacement direction area deviated during the path advancement is extracted, and the order of each offset segment in the path arrangement is recorded. The spatial layout sequence diagram of the path advancement sequence is established. For example, the spatial direction of the middle segment P302 to P306 of path B is continuous on the time axis, but the offset angle of the position P307 in the spatial diagram is greater than 15 degrees, which is then judged as an offset point segment. Its actual displacement position is drawn on the overall path diagram and included in the offset point group in the path advancement sequence. By summarizing such segments in all paths and forming a graphical representation, the stress propagation dislocation segment identification diagram is finally obtained.

[0129] The specific steps of S5 are:

[0130] S501: Based on the pile segment information and shear dilatancy direction matching data in the stress propagation dislocation segment identification map, the contact surface state in the pile segment is extended in a path sequence along the shear dilatancy mutation direction, the strike change of the pile-soil contact boundary is scanned along the path direction, and the contact surface response characteristics of the pile segment positions are arranged in sequence along the directional path to obtain a contact surface directional response path sequence;

[0131] First, the distribution position of each pile segment in the different direction path is read, and the pile segment number corresponding to each shear dilatancy mutation direction is expanded point by point. The path clues in the shear dilatancy mutation direction are matched with the pile segment arrangement direction. For each path clue, the sequence pile segments are extracted from the starting pile segment along the shear dilatancy direction in the figure. The image information of each pile-soil contact interface is read, and the boundary performance of the pile segment under the path in the image is arranged in sequence. The profile change of each pile segment contact boundary is scanned, and the profile difference of each profile line at the pile segment junction position is taken as the basis for judging the contact state change. For example, if the path direction is θ = 45°, the profile offset angle between pile segments P203 and P204 exceeds ± 10°, it can be determined that there is a trend fluctuation phenomenon at this position. At this time, continue to read the pile segment data of P205, P206, etc. in the same direction, and continue to add the boundary performance to the path sequence to form a set of sequentially corresponding pile segment contact boundary descriptions. Then, the same operation is performed on all paths with shear dilatancy mutation direction identifiers in the figure. The pile segment sequence on each path is expanded, and the arrangement order is determined based on the pile segment number in each path. Whether the trend shown in the contact boundary image is consistent or has a phased fluctuation phenomenon is confirmed. For example, in a certain path, pile segments P301 to P306 maintain a similar trend, and P307 starts to mutate in angle. Then, the path after P307 can be divided into another continuous change sequence. Through the sequential extraction and parallel arrangement of the arrangement order of each pile segment in the path and the contact surface performance, the contact boundary description chain for different path directions is formed. Finally, the contact surface boundary trend displayed in each path is combined to obtain the contact surface direction response path sequence.

[0132] S502: Based on the contact surface direction response path sequence, the extension trend of the pile-soil interface boundary line is processed in the compaction disturbance direction. The trend difference between the paths is compared, the offset performance between the paths is identified according to the cross-trend relationship, and the interface boundary information change characteristics are obtained.

[0133] First, the reference direction of the compaction disturbance is divided based on the obtained path direction, all paths are merged and segmented, the boundary line profile in each path is flattened in the order of stake segment number, and each segment path is unfolded in the compaction disturbance direction. Starting from the starting stake segment, the linear trend of the contact surface boundary is continuously read and its trajectory is extended, and the trend change is recorded. Taking paths P101 to P108 as an example, when the boundary line angles of P101 to P104 are maintained at 35°±3°, and P105 starts to appear a deflection of 45° to 60°, it can be considered that the trend changes during the extension. Subsequently, the same operation is performed on other paths, the boundary trend line of each path is unfolded in the direction order, the corresponding stake segment positions of all paths are compared in angle, and the included angle with the disturbance reference direction is calculated. If a pair of paths forms an intersection at P203, and the intersection angle reaches 20° or more, it can be judged that there is a directional deviation relationship at this point. At this time, the path number and intersection characteristics at this point are recorded, the intersection identification action of the path is continued, and all intersection points are placed on the boundary map. The angle mutation segment appearing at the intersection between the paths is tracked horizontally, the stake segment number range in the path section with continuously increasing intersection angle is identified, and the boundary twist or turning characteristics of this path section in space are further determined. Combined with the spatial distribution trajectory between these intersection points, the trend channel of the boundary trend change is formed by continuously connecting and extending the intersection direction characteristics. Finally, all regions with intersection relationship or trend deviation phenomenon between the paths are drawn in a unified coordinate space, and the boundary information change characteristics are obtained.

[0134] S503: Based on the boundary information change characteristics, the trend arrangement of the node stake segment in the contact surface direction response path sequence is called, the corresponding disturbance direction combination is sequentially embedded into the shear dilation mutation path, the sequence is matched synchronously, the response distribution of the stake segment direction combination is marked, and the stake-soil contact surface response state structure partition map is obtained.

[0135] First, the nodes of the contact surface direction response path sequence need to be unfolded according to their number sequence, the boundary angle values of each pile segment in the disturbance direction are extracted, the strike trajectory in the image path is called, the boundary contour points of the pile segment are arranged in sequence according to the number, the start point and end point boundary coordinates of the pile segment are selected to form a line segment, the included angle value θi of adjacent line segments is calculated, the included angle value is converted according to the cosine value of the vector composed of the start and end points, it is judged whether the included angle value is in the direction jump interval, if θi exceeds the set threshold Δθ, Δθ is set to 20°, the node is recorded as a strike jump point; continue to scan the subsequent pile segment along the path, similarly extract the included angle of the line segment, form a direction jump node set, for example, the included angle between pile segment numbers P105 and P106 is 18°, P106 and P107 is 26°, only the latter exceeds the threshold, P107 is marked as a jump point, then, all jump point sequences are embedded according to the shear dilation mutation path number, the corresponding node number is searched in each mutation path, and the pile segment where the jump point is located is aligned with the shear dilation path pile segment according to the number, each shear dilation mutation path is taken as a reference channel, and all matching jump points are nested and marked on it; then, the included angle values in each disturbance path direction group are matched with the included angle values in the shear dilation path, and the matching is based on the included angle change trend, if the continuous rising section of the direction in the disturbance path is consistent with the shear dilation path, it is determined that it is a embeddable channel, and the path number is recorded; for example, the included angle sequence of shear dilation path numbers P201 to P206 is 15°, 18°, 22°, 27°, the included angle sequence of disturbance path numbers P301 to P306 is 14°, 19°, 21°, 28°, the average difference of the included angles of the two is less than ±3°, so they are considered as trend matching paths, and P301 to P306 are embedded in the corresponding positions of P201 to P206; then, the response distribution in the pile segment direction combination is marked, which is to count the number of embedded paths in each shear dilation mutation path and its start and end numbers to form a pile segment response section mapping table, for example, the embedded disturbance paths P501 and P502 in the shear dilation path P401 are continuously coincided in the P403 to P406 section, so the response distribution in this section is a high-frequency combination section, and the response frequency is 2, the threshold T is defined as 3, if the response frequency is less than T, it is determined as a low-response combination section, otherwise it is a high-response section, and the response level of each section is recorded. Finally, the above combination is marked on the path strike graph to obtain the response state structure zoning graph of the pile-soil contact surface.

[0136] Please refer to Figure 2 A three-dimensional finite element analysis system for bearing characteristics of steel pipe pile, comprising:

[0137] The shear dilation trend identification module obtains the shear strain trajectory and volume deformation change sequence in the layered area of the steel pipe pile side slip zone, merges the nodes, gradually maps the shear strain and volume deformation data in the same direction, and identifies each shear dilation mutation point in the direction. The distribution range of the mutation point is merged to obtain the main control direction group of the shear dilation trend.

[0138] The disturbance boundary tracking module maps and compares the cross-section structure displacement images of the original soil interface of the grouting layer in the initial and final stages of loading based on the calibrated direction range in the shear dilation trend dominant direction group, judges the consistency of the deformation deviation direction and the contact boundary, and calibrates the profile change position after the boundary displacement, to obtain a grouting disturbance response boundary mapping diagram;

[0139] The settlement trend analysis module controls the pile top node loading process displacement path record sequence based on the mapping result in the grouting disturbance response boundary mapping diagram, archives the response change time sequence and tracks the direction change node, compares the response lag relationship between the pile body and the adjacent pile body in sections, to obtain a pile group settlement trend deviation distribution diagram;

[0140] The loading path reconstruction module synchronously tracks the continuous path information of the longitudinal loading reaction force based on the lag response pile position number in the pile group settlement trend deviation distribution diagram, reconstructs the transmission node order of the pile body reaction force between the loading steps, calibrates the section number according to the stress path conduction sequence difference position, to obtain a stress propagation misplacement section identification diagram, which is transmitted to the contact response identification module;

[0141] The contact response identification module performs direction corresponding processing on the contact surface state in the differential section along the shear dilation mutation direction based on the pile section information and shear dilation direction matching data in the stress propagation misplacement section identification diagram, cross-comparison of the contact boundary information in the compaction disturbance direction, identification of the response performance of the contact section under the action of two-way, to obtain a pile-soil contact surface response state structure partition diagram.

[0142] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any skilled person in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. Three-dimensional finite element analysis method for bearing characteristics of steel pipe piles, characterized by: The following steps are involved: S1: Obtain the shear strain trajectory and volume deformation sequence in the side slip zone of the steel pipe pile, map the shear strain and volume deformation data according to the direction, locate the shear expansion mutation point, arrange the directions according to the spatial distribution of the mutation points, and obtain the main control direction group of the shear expansion trend; S2: Based on the calibrated direction range in the main control direction group of the shear dilatancy trend, mapping the displacement images of the interface between the grouting layer and the original soil at the initial and final stages of loading, determining the relationship between the deformation offset direction and the boundary position, and obtaining a grouting disturbance response boundary mapping diagram; S3: Based on the mapping results in the grouting disturbance response boundary mapping map, the displacement path records are retrieved by comparing the pile body number sequence, and the response changes are compared with the hysteresis nodes to obtain the pile group settlement trend offset distribution map; S4: based on the hysteresis response pile position numbers in the pile group settlement trend offset distribution map, tracing the continuous path of the loading reaction force, reconstructing the order of the transmission nodes, identifying the locations of the conduction sequence differences in the path, and obtaining a stress propagation dislocation section identification map; S5: Based on the pile segment information and shear dilation direction data in the stress propagation dislocation segment identification map, the disturbance boundary characteristics are compared along the mutation direction to identify the response difference and obtain the pile-soil interface response state structural partition map; The specific steps of mapping the grouting disturbance response boundary are as follows: S201: Based on the calibrated direction range in the main control direction group of the shear dilatancy trend, mapping the cross-sectional structural displacement images in the interface between the grouting layer and the original soil at the initial and final stages of loading, corresponding to the directional displacement path, screening the area where the deformation direction turns at the boundary contour, and obtaining an initial direction mapping sequence; S202: Based on the direction paths in the initial direction mapping sequence, extract the connected directions of the boundary points in the image, determine the correspondence between the continuous displacement paths near the boundary line and the contact boundary directions, calculate the angle change between the boundary direction paths, and determine the concentrated location of the change inflection points to obtain the boundary direction convergence change interval; S203: Based on the regional path in the boundary direction convergence change interval, identifying the directional connected segments of the boundary region images before and after loading, checking the difference in the continuous direction of the contours in adjacent segments, and drawing the direction-shifted area at the contact boundary position to obtain a grouting disturbance response boundary mapping diagram; The specific steps of the pile group settlement trend deviation distribution diagram are: S301: Based on the regional disturbance contour results presented in the grouting disturbance response boundary mapping diagram, the corresponding pile body number sequence is called to obtain the displacement path sequence of each pile top node in the loading stage, and the direction change process under the differentiated time step in the path is identified in the number sequence, the node path direction evolution characteristics are extracted, and the node direction change characteristics are obtained; S302: Based on the nodes of the position point set in the node direction change feature, the displacement path difference within the loading time period is compared according to the adjacent pile body numbers, the timing difference between the node response start and transmission is identified, and the response start delay ratio between the adjacent pile bodies is calculated to obtain a delayed response ratio distribution group; S303: Based on the delay value sequence of the numbered pile segments in the delayed response ratio distribution group, the pile body number arrangement direction is compared with the change position in the offset sequence, the path direction offset relationship is extracted in the delay change sequence, and a pile group settlement trend offset distribution map is obtained.

2. The three-dimensional finite element analysis method for the bearing characteristics of steel pipe piles according to claim 1 is characterized in that: The shear expansion trend main control direction group includes a shear strain mutation point sequence, a volume deformation mapping relationship, and a main control direction angle range; the grouting disturbance response boundary mapping diagram includes a contour offset zone, deformation direction consistency characteristics, and a boundary disturbance response line; the pile group settlement trend offset distribution diagram includes a displacement path change trajectory, a response lag comparison node, and a settlement trend offset interval; the stress propagation dislocation section identification diagram includes a reaction force transmission node sequence, stress sequence differences between loading steps, and dislocation section number identification; the pile-soil contact surface response state structural zoning diagram includes a shear expansion direction response type, a two-way action contact characteristic, and a structural zoning identification result.

3. The three-dimensional finite element analysis method for the bearing characteristics of steel pipe piles according to claim 1 is characterized in that: The homing dilatancy mutation point refers to a mutation point in the shear strain trajectory and volume deformation direction sequence where the shear strain continues to increase and the volume deformation direction suddenly reverses; The comparison of response changes and delayed nodes refers to analyzing the displacement path record time sequence of each pile top node during the loading phase, identifying the start time of the node response during the loading process, and comparing it with the response time difference between adjacent nodes and the pile body to capture the time-delayed nodes.

4. The three-dimensional finite element analysis method for the bearing characteristics of steel pipe piles according to claim 1 is characterized in that: The reconstructing of the transfer node order refers to tracing the transfer path of the reaction force between the pile segments during the loading process after identifying the delayed response pile position, and identifying the difference position in the transfer order; The comparison of disturbance boundary characteristics along the mutation direction refers to scanning the pile-soil contact surface boundary along the direction based on the existing shear expansion mutation direction, identifying and comparing the differences in boundary direction, contour extension trend and junction information changes in the differentiated path.

5. The three-dimensional finite element analysis method for the bearing characteristics of steel pipe piles according to claim 1 is characterized in that: The specific steps of S1 are: S101: Obtain the shear strain trajectory and volume deformation change sequence in the stratified area of ​​the steel pipe pile side slip zone, correspond each set of shear strain direction values ​​and volume deformation direction values ​​along the direction number, and analyze the change amplitude between positions with the same direction along the node sequence to obtain the corresponding section of the direction map; S102: Based on the corresponding section of the direction mapping, identifying the relationship between the continuous increment of the shear strain value in the direction advancement path and the switching of the volume deformation direction, and locating the sequence number at the direction point where the shear strain increases and the volume deformation direction reverses, to obtain a shear dilation direction jump position group; S103: Based on the dilatancy direction jump position group, the direction number path where the direction jump is located is screened, and the direction channel data sequence of the direction continuous trend is extracted in combination with the node sequential connection direction to obtain the dilatancy trend main control direction group.

6. The three-dimensional finite element analysis method for the bearing characteristics of steel pipe piles according to claim 1 is characterized in that: The specific steps of S4 are: S401: Based on the hysteresis response pile position number in the pile group settlement trend offset distribution diagram, the longitudinal reaction force data of the corresponding pile segment during the loading step are called, the arrangement process of the pile segment reaction force transmission path on the time axis within the loading step is tracked in the order of the number, and the continuity and discontinuity characteristics of the path are traced to obtain the reaction force path advancement sequence; S402: Based on the reaction path advancement sequence, according to the time sequence of the longitudinal reaction force responses of the pile segments within the loading step, a horizontal comparison is performed on the step correspondence between the paths, and pile segment sequences with discontinuous responses are screened out to obtain a path response sequence difference interval; S403: Based on the path response sequence difference interval, the arrangement positions of the continuous advancement segment and the discontinuous response segment in the loading direction are tracked, the deviated position areas in the response trajectory are identified along the advancement path, and the order and spatial layout of the areas in the advancement path are divided in sequence to obtain a stress propagation dislocation segment identification map.

7. The three-dimensional finite element analysis method for the bearing characteristics of steel pipe piles according to claim 1 is characterized in that: The specific steps of S5 are: S501: Based on the pile segment information and dilatancy direction matching data in the stress propagation dislocation segment identification map, extending the contact surface state in the pile segment along the dilatancy mutation direction in a path sequence, scanning the strike change of the pile-soil contact boundary along the path direction, and arranging the contact surface response characteristics of the pile segment positions along the directional path to obtain a contact surface directional response path sequence; S502: Based on the contact surface direction response path sequence, the extension trend of the pile-soil interface boundary line is processed section by section in the compaction disturbance direction, the direction differences between the paths are compared, and the offset performance between the paths is identified according to the cross-direction relationship to obtain the boundary information change characteristics; S503: Based on the change characteristics of the boundary information, the direction arrangement of the node pile segments in the contact surface direction response path sequence is called, the corresponding disturbance direction combinations are sequentially embedded in the shear expansion mutation path, the sequence is synchronously matched, and the response distribution of the pile segment direction combination is marked to obtain the pile-soil contact surface response state structure partition diagram.

8. A three-dimensional finite element analysis system for the bearing characteristics of steel pipe piles, characterized in that: The system is used to implement the three-dimensional finite element analysis method for the bearing characteristics of steel pipe piles according to any one of claims 1 to 7, and the system includes: The dilatancy trend identification module obtains the shear strain trajectory and volume deformation change sequence in the stratified area of ​​the steel pipe pile side slip zone, corresponds to the merged nodes, and gradually maps the shear strain and volume deformation data in the same direction. The dilatancy mutation points in each direction are located and identified, and the distribution range of the mutation points is merged to obtain the main control direction group of the dilatancy trend. The disturbance boundary tracking module maps and compares the cross-sectional structural displacement images of the undisturbed soil interface zone of the grouting layer at the initial and final stages of loading based on the calibrated direction range in the main control direction group of the shear dilatancy trend, determines the consistency of the deformation offset direction with the contact boundary, and calibrates the contour change position after the boundary displacement, thereby obtaining a grouting disturbance response boundary mapping diagram; The settlement trend analysis module compares the mapping results in the grouting disturbance response boundary mapping diagram with the pile body number sequence, retrieves the displacement path record sequence of each pile top node during the loading process, archives the response change time series and tracks the direction change nodes, and compares the response hysteresis relationship between the pile body and the adjacent pile bodies in sections to obtain the pile group settlement trend offset distribution diagram; The loading path reconstruction module synchronously tracks the continuous path information of the longitudinal loading reaction force based on the hysteresis response pile position number in the pile group settlement trend offset distribution map, reconstructs the transmission node order of the pile body reaction force between loading steps, calibrates the section number according to the difference in the stress path conduction sequence, obtains the stress propagation dislocation section identification map, and transmits it to the contact response identification module; The contact response identification module is based on the pile segment information and shear dilatancy direction matching data in the stress propagation dislocation segment identification map, performs directional correspondence processing on the pile-soil contact surface state in the differentiated segment along the shear dilatancy mutation direction, cross-compares the contact boundary information in the compaction disturbance direction, identifies the response performance of the contact segment under bidirectional action, and obtains the pile-soil contact surface response state structural partition diagram.

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