3956 results about "Bearing capacity" patented technology

The invention relates to the field of building structure safety detection, and discloses a building structure anti-seismic performance monitoring method and system. The method comprises the following steps: acquiring multi-source response data such as acceleration, displacement, strain and inclination angle; obtaining a structure standard response based on wavelet denoising and standardization processing; adopting a multi-order modal recognition algorithm to extract structural dynamic characteristic parameters; performing structural damage evaluation based on the modal change index, and combining the yield strength, the load index and the displacement margin to calculate the residual bearing capacity of the structure; and finally, outputting an anti-seismic grade early warning signal. The system comprises a structure response acquisition module, a modal identification and damage evaluation module and a residual bearing capacity calculation and early warning module. According to the method, real-time quantitative analysis of the performance of the structure under the earthquake or load effect can be achieved, the evaluation precision is high, the applicability is high, and the wide engineering popularization value is achieved.

The invention discloses a spiral anchor foundation bearing effect evaluation method and system, and relates to the technical field of finite element analysis, and the method comprises the steps: building a soil body and spiral anchor finite element model, setting boundary conditions, and obtaining finite element data; according to the finite element data, a local damage variable is introduced based on a stress-strain degradation function, local shear band development is simulated, first damage data are generated, and the first damage data comprise a first stress-strain curve and a first local damage variable; layering the soil body, and optimizing the first damage data based on intra-layer constraints to obtain second damage data; calculating full-field stress, displacement and bearing capacity for effect evaluation based on a finite element solver according to the second damage data; the problem of inaccurate evaluation of the screw anchor effect caused by the nonlinear behavior and the layered heterogeneous effect of the soil body is solved.

The invention provides a method and system for predicting the uplift bearing capacity of a mud mixed pile. According to the method, modeling is carried out by integrating geomechanics and monitoring data. The method comprises the following steps: firstly, acquiring geometric parameters of a multi-layer heterogeneous soil layer interface, constructing a database through a mechanical test, and improving the reliability by combining gradient recognition and cooperative verification of pile deformation and load data; dividing longitudinal segmentation units, adjusting anti-slip parameters to generate a space mapping table, establishing a debonding dynamic model containing an interlayer retardation effect, simulating a debonding expansion process, and outputting load evolution data. And judging the maximum load of the critical state based on data convergence analysis, and taking the maximum load as a predicted value of the uplift bearing capacity. According to the technical scheme, through dynamic parameter mapping and debonding process simulation, accurate prediction of the uplift bearing capacity of the pile foundation in a complex soil layer is achieved, and the defect that a traditional model is insufficient in characterization of interlayer heterogeneity and dynamic debonding behaviors is overcome.

The embodiment of the invention discloses a numerical optimization method and device considering bearing capacity of a steel frame and a concrete precast slab, equipment and a medium. The method comprises the following steps: acquiring geometric parameters, material attributes and connection parameters between the steel frame and the concrete precast slab corresponding to the steel frame and the concrete precast slab respectively, constructing a geometric model based on the geometric parameters, performing finite element mesh division, assigning the material attributes and the connection parameters to generate a finite element model, and performing finite element mesh division on the finite element model; static load analysis and dynamic load analysis are conducted on the finite element model to obtain bearing capacity response, continuous optimization is conducted by changing set parameters, material attributes and connection parameters, the influence of different parameters on the bearing capacity is analyzed, an optimal parameter combination is found, the bearing capacity is maximized, and the bearing capacity is improved. Marking stress concentration and weak areas based on the optimal parameter combination; according to the technical scheme, the accuracy of the steel frame-concrete prefabricated slab model can be improved, and the effectiveness and efficiency of parameter optimization on stress concentration and weak areas are improved.

The invention relates to the technical field of geotechnical engineering, and discloses a method, device and equipment for predicting the bearing capacity of an offshore wind power single pile and a medium, and the method comprises the steps that actual measurement data of different stratums where the single pile is located are obtained based on a pore pressure static sounding test; determining side friction resistance and unit pile end resistance of different stratums where the single pile is located based on measured data; the BP neural network model is trained based on preset single pile attribute data, the side friction resistance and the single pile end resistance, and a single pile bearing capacity prediction model is obtained; optimizing the single-pile bearing capacity prediction model based on a genetic algorithm to obtain a data processing type single-pile bearing capacity prediction model with gradually increased fitness; and solving the data processing type single-pile bearing capacity prediction model with gradually increased fitness to obtain an optimal solution of the single-pile bearing capacity. According to the method, the purpose that the accurate single-pile bearing capacity can be obtained only by conducting the pore pressure static sounding test subsequently is achieved, and the prediction accuracy is improved.

The invention provides a method and system for estimating the vertical bearing capacity of a steel pipe pile, and relates to the technical field of pile foundation engineering.The method comprises the steps that a static cone penetration test is conducted on a seabed stratum needing to be arranged for a steel pipe pile foundation, experimental data are obtained and subjected to normalization processing, soil behavior types are divided, and soil layer mechanical parameters are inverted; calculating side friction resistance and end resistance of the steel pipe pile based on the soil layer mechanical parameters to obtain initial static ultimate bearing capacity; historical equivalent cyclic load experimental data of waves in the construction sea area are obtained, an equivalent cyclic load reduction coefficient, a liquefaction reduction coefficient and a time-varying corrosion reduction coefficient are constructed, and a comprehensive time-varying reduction coefficient is constructed; the initial static ultimate bearing capacity is corrected based on the comprehensive time-varying reduction coefficient, the vertical bearing capacity of the steel pipe pile in the long-term service period is predicted, and the time-varying ultimate bearing capacity is obtained; setting an evaluation threshold according to the time-varying ultimate bearing capacity, dynamically adjusting a bearing capacity grading threshold interval, and outputting a bearing capacity grading evaluation result.

The invention provides a desert photovoltaic support pile foundation uplift bearing capacity detection and construction parameter optimization method, and relates to the technical field of construction optimization, and the method comprises the following steps: dividing construction subareas according to soil parameter information of a desert target area, carrying out test pile detection in each construction subarea, and establishing a distribution rule of uplift bearing capacity of a pile-soil interface; the pile foundation diameter, the pile foundation burial depth and the pile foundation surface treatment mode serve as variables, a multi-objective optimization function including an uplift bearing capacity stability objective, an uplift bearing capacity redundancy objective and a construction efficiency objective is established, and the weight coefficient of the multi-objective optimization function is dynamically adjusted along with the environment temperature and sand bed migration; solving the multi-objective optimization function by adopting a particle swarm algorithm to obtain an optimal construction parameter combination of each construction subarea; and the optimal construction parameter combination is adopted for pile foundation construction, a pile foundation is selected for uplift bearing capacity rechecking, a rechecking result is fed back to the multi-objective optimization function, and dynamic fine adjustment is conducted on the construction parameters.

According to the pile foundation pile sinking monitoring method, device and equipment and the storage medium, the pile foundation pile sinking image is obtained through the collecting equipment arranged at the preset position, the pile foundation pile sinking image comprises the to-be-monitored pile foundation, and the to-be-monitored pile foundation is provided with a pile body scale; calculating the actual size of a unit pixel according to the pile body scale so as to determine a vertical pixel calibration value; according to a preset mark point and the vertical pixel calibration value, pile foundation pile sinking parameters are determined; and the pile sinking parameters of the pile foundation are input into a bearing capacity prediction model, and the predicted bearing capacity of the to-be-monitored pile foundation is obtained. The image acquisition device arranged at the preset position is used for acquiring the pile sinking image of the pile foundation in real time, pixel calibration is carried out in combination with the pile body scale, and key parameters in the pile sinking process of the pile foundation can be accurately calculated, so that a reliable basis is provided for prediction of the bearing capacity of the pile foundation, the monitoring precision and efficiency are greatly improved, and the cost is reduced. And errors possibly caused by manual measurement are avoided.

The invention provides an intelligent prediction method and device for the bearing capacity of a pile foundation, and the method comprises the steps: forming an in-situ test sample based on an engineering geology in-situ test; the optimal geological parameters of the karst geology are obtained through inversion of the proxy model; and geological parameters of the field test under multiple working conditions are obtained, and a pile foundation field test sample library is formed. Obtaining pile foundation bearing performance parameters of various karst geologies under a pile foundation reduced scale model experiment to form a pile foundation reduced scale model sample library; carrying out analogue simulation on the optimal geological parameters of each karst geology to form a pile foundation analogue simulation sample library; constructing a pile foundation bearing capacity training sample library by the three sample libraries; training the pile foundation bearing capacity prediction model; and geological parameters of a construction site are input into the pile foundation bearing capacity prediction model, and the pile foundation model of the actual construction site is optimized and adjusted based on the obtained geological parameters. According to the method, data of four research paradigms are fused, and a more comprehensive and accurate intelligent prediction method for the bearing capacity of the pile foundation is constructed.

The invention relates to a machine learning-based scouring damage bridge buckling load prediction method and system, and belongs to the technical field of machine learning and structural engineering. The prediction method comprises the steps of obtaining original data, preprocessing the original data, constructing a LightGBM machine learning model, and evaluating and verifying the constructed model by adopting multiple performance evaluation indexes. According to the method, key variables such as bridge structure parameters and foundation soil physical property indexes are comprehensively considered, a large sample database covering a large number of scouring combinations is constructed, and the critical buckling load of the structure is accurately calculated as an output target by using a pier-bearing platform-pile structure system buckling analysis method after scouring damage based on an energy method. A multivariable nonlinear mapping relation is established in combination with an ensemble learning algorithm, traditional complex calculation is replaced, and the method has good engineering adaptability and universality and can be suitable for rapid prediction of the buckling bearing capacity under different parameter bridges, different foundation forms and complex scouring conditions.

According to the offshore wind turbine single pile rigidity numerical simulation method considering long-term circulation and scouring, the accuracy and the calculation convenience are both considered in model building through the linear elastic steel pipe pile model and the Mohr-Coulomb soil body model. By calculating the horizontal ultimate bearing capacity of the single pile, combining the ultimate analysis method and the p-y curve calculation method, the influence of different scouring depths on the fan is considered, the horizontal load bearing capacity and inherent frequency evolution of the single pile are comprehensively measured, and a basis is provided for design and safety evaluation. A sandy soil rigidity attenuation model is established for secondary development of Abaqus and verified, and the rigidity change of sandy soil under long-term cyclic loading is considered, so that the simulation precision is improved. And the numerical model is tested and verified to ensure the reliability. And the accumulated lateral displacement of the steel pipe pile can be accurately predicted, the influence rule of cyclic load times, soil elasticity modulus and embedding depth factors on displacement development is disclosed, wind power engineering design optimization is assisted, and economical efficiency and safety are improved.

The invention discloses equipment for realizing modularized soil in-situ injection remediation by adopting a digital control system. The equipment comprises a carrier and an injection mechanism arranged on the carrier, the injection mechanism can be used for injecting medicaments into the deep underground soil for remediation; in the remediation process, a second sleeve in the injection mechanism can be rotated to be matched with the pushing mechanism to loosen the compacted soil outside the channel drilled by the drill bit, the agent spraying area is enlarged, and diffusion of the agent and fusion of the agent and the soil can be accelerated; meanwhile, the first sleeve can protect the second through hole from being blocked and keep smooth medicament injection, single-hole continuous dynamic fixed-depth injection is adopted, medicament adding parameters are controlled and optimized, and medicament injection parameters can be accurately controlled; the problem of repairing the sandwich layer is solved in a small-caliber bottom-to-top injection mode, meanwhile, the advantage of maintaining the bearing capacity of the foundation after construction is achieved, and the diffusion and injection effects of the medicament can be guaranteed by designing air and medicament nozzles and drilling tools.

The invention provides a single pile bearing capacity prediction method based on an XGBoost machine learning algorithm, comprising the following steps: (1) acquiring and preprocessing test data including soil layer input parameters, pile parameters and construction parameters, and dividing the preprocessed test data into a test set and a training set; (2) constructing a machine learning model in a pile foundation design stage according to the soil layer input parameters and the pile parameters, constructing a machine learning model in a pile foundation construction stage according to the soil layer input parameters, the pile parameters and the construction parameters, and respectively optimizing the two machine learning models by adopting a Bayesian optimization algorithm; and (3) the two optimized machine learning models are used for calculating the single-pile bearing capacity in the pile foundation design stage and the single-pile bearing capacity in the construction stage according to needs. According to the method, influence factors of all stages are comprehensively considered, algorithm learning is carried out on the influence factors, the bearing capacity of the reinforced concrete prefabricated pipe pile can be rapidly and effectively predicted, and the method can be used for optimizing the pile length design, reducing the pile material cost and improving the construction quality.

The invention provides a marine unfavorable geology reef limestone grouting strength prediction method based on a pore structure. The method comprises the following steps: calculating a reef limestone rock pore value of a reef limestone rock pore volume accounting for a reef limestone rock mass volume; performing size classification on the equivalent diameters of the communicated pores in the reef limestone, and calculating the volume ratio of each type of communicated pores; calculating the pore sphericity of the pore particles according to the pore particle surface area and the pore particle volume; classifying the pore particles according to the pore sphericity, and calculating the sphericity ratio of each type of pore particles; calculating a seepage coefficient based on the pore value of the reef limestone rock, the volume ratio of various communicated pores and the sphericity ratio of various pore particles; calculating the flow of the slurry flowing in the reef limestone rock under the action of different pressures according to the seepage coefficient; and calculating the tensile strength of the reef limestone rock based on the flow before and after grouting. Through accurate permeability analysis, the construction risk and cost are reduced, and meanwhile the bearing capacity of the foundation base is improved.

The invention discloses a positive screw pile foundation axial ultimate uplift bearing capacity calculation method. The method comprises the steps that a pile-soil interface contact normal pressure stress function and a contact tangential friction stress function are constructed; constructing an equivalent relationship between the uplift resistance on the right-hand screw pile drawing surface and the shear resistance on the cylindrical shear failure surface of the foundation soil body, and obtaining the horizontal force and the circumferential torque of the soil body acting on the right-hand screw pile drawing surface; obtaining an equivalent concentrated load of a horizontal force and an action point location thereof; the radial load of the foundation soil body acting on the right-hand screw pile drawing face is obtained, and the additional radial stress on the cylindrical shear failure face in the foundation soil body is obtained; obtaining application conditions of an additional shear resistance calculation formula according to an additional radial stress limit summation calculation formula; and a positive screw pile foundation axial ultimate uplift bearing capacity calculation formula is constructed, and the positive screw pile foundation axial ultimate uplift bearing capacity calculation formula is obtained. The problem that the axial ultimate uplift bearing capacity of the positive screw pile foundation cannot be accurately obtained through an existing method is solved.

The invention provides a finite element-based method for estimating pulling-out ultimate bearing capacity of a grouting screw anchor in gravelly soil, and relates to the technical field of civil structure engineering.A three-dimensional finite element model containing the grouting screw anchor and surrounding gravelly soil is established, model parameters cover the structure and material characteristics of the grouting screw anchor, and the grouting screw anchor and the surrounding gravelly soil are subjected to finite element modeling; a coordinate axis is established with the center of the anchor bottom as an original point for grid division, a stress concentration area is analyzed, principal stress is calculated to serve as critical bearing stress, vertical pull-out loads are applied step by step through a grouting pull-out test, a pull-out stress influence area is determined, soil stress of the area is analyzed, and soil binding power and friction force are calculated. And a grouting coefficient and a rock crack coefficient are generated, soil parameters are corrected, and the ultimate pulling bearing capacity of the grouting screw anchor is comprehensively obtained. According to the method, the pulling ultimate bearing capacity of the grouting screw anchor is accurately evaluated by establishing the three-dimensional finite element model and the graded loading experiment.

The invention discloses a near-slope foundation bearing capacity estimation method and system considering slope body stability, and the method comprises the steps: collecting geological data and environmental data of a target region, constructing a target region simulation model, and carrying out the simulation obtaining of the slope body parameter changes of the target region under different environments and load effects; determining a potential sliding surface based on the simulated slope parameter change, a preset sliding surface determination mode and a preset slope stability coefficient calculation method, and calculating a slope stability coefficient of the target area; determining a geological risk level of the target area, and when the geological risk level is greater than a preset risk level, selectively collecting a slope surface image of the target area, and calculating a soil parameter adjustment value; and correcting the foundation bearing capacity formula by using the slope stability coefficient or the slope stability coefficient recalculated according to the soil parameter adjustment value, and outputting an estimated value of the foundation bearing capacity. According to the method, the slope stability can be considered under the complex terrain condition, and the bearing capacity estimated value of the near-slope foundation can be obtained more accurately.

The invention discloses a high-rise shear wall structure anti-seismic effect evaluation method and system, and particularly relates to the technical field of high-rise shear walls. The method comprises the following steps: accurately collecting low-cycle fatigue parameters, constructing a concrete and steel bar degradation model considering a fatigue effect, applying the model to anti-seismic analysis of a shear wall structure, simulating the influence of main shock and multiple aftershock loading on structural performance, drawing a bearing capacity degradation curve according to multiple loading results, and analyzing a degradation speed abnormal state. The risk that the structural rigidity and the bearing capacity are abnormal is judged by combining the change of the residual rigidity and the bearing capacity, the risk is divided into high, medium and low levels, and proper reinforcement or prevention measures are provided for different risk levels, so that the defect that the material fatigue effect is not fully considered in the existing anti-seismic evaluation is effectively overcome, and the anti-seismic evaluation accuracy is improved. According to the method, the damage accumulation condition of the high-rise shear wall structure in frequent aftershocks can be predicted more accurately, so that the risk of premature failure of the structure is reduced, and the durability and safety of a building in an earthquake are improved.

The invention relates to the technical field of tunnel engineering, and discloses a training method and device of a tunnel bearing capacity prediction model, equipment and a medium, and the method comprises the steps: obtaining a training data set based on a finite element limit analysis model; iteratively training the reference models of different types according to the training data set, and determining a plurality of target reference models; iteratively training a plurality of different types of meta learners based on the plurality of target reference models and the training data set, and determining a target meta learner; and a fusion model is constructed on the basis of the target element learning device and the multiple target reference models, and the fusion model is used for carrying out soil bearing capacity prediction according to the characteristic parameters corresponding to the target tunnel engineering. Therefore, the fusion model for predicting the bearing capacity of the soil body is obtained, and the prediction efficiency is improved on the basis of ensuring the prediction accuracy of the bearing capacity of the soil body.

The invention discloses a monitoring control system for static pressure pile machine construction. The monitoring control system comprises a central control system, a man-machine interaction screen display module, a static pressure pile machine operation module, a construction data acquisition module, a welding quality monitoring module, a pile foundation bearing capacity prediction module and a cloud data storage and presentation module. The invention further discloses an implementation method of the monitoring control system for static pressure pile machine construction. Through linkage of the central control system and the static pressure pile machine, efficient automation and accurate control of the construction process are achieved; in the construction process, the leveling and pile pressing operation of the pile clamping platform and the pile pressing platform can be regulated and controlled through construction data collected in real time, it is ensured that the prestressed concrete pile vertically enters the soil and reaches the designed pile pressing depth, and deviation is avoided; the welding quality monitoring module can monitor the welding quality in real time, and it is ensured that the construction quality meets the standard.

The invention relates to the technical field of foundation construction, and provides a building foundation construction method under complex geological conditions. The method comprises the following steps: S1, sampling and detecting land by using equipment, and comprehensively analyzing soil layer, underground water level and geological risk; s2, a foundation pit geometrical shape and a supporting scheme are designed according to an exploration result, and construction safety is ensured; s3, an underground descending well is set up to lower the underground water level of the construction area; s4, a deep mixing pile is adopted for foundation reinforcement, and the bearing capacity of a soil body is improved; s5, the soil body is improved, and the soil strength and stability are improved; and S6, the foundation pit is monitored in real time, and the displacement, the underground water level and the soil pressure of the foundation pit are monitored. By adopting an advanced geological detection technology, the properties of underground soil and rocks can be accurately evaluated before construction, and the measure can find potential geological hidden dangers in time, so that corresponding safety measures are formulated, the risk in the construction process is reduced, and the safety of constructors is ensured.

The invention provides a reverse self-balancing pile foundation bearing capacity detection method based on prefabricated steel pipe piles, and relates to the technical field of pile foundation detection, and the method comprises the steps that the assembled prefabricated steel pipe piles are constructed at preset elevation positions of a target test field; obtaining first record data and second record data; on the basis of the first recorded data and the second recorded data, the total compressive bearing capacity and the total uplift bearing capacity of the prefabricated steel pipe pile are obtained through calculation according to a reverse self-balancing method; wherein a pile body load box in the loading pile body section is used for loading, the upper pile body and the lower pile body are driven to deform oppositely, and at least the stress of the pile body load box and the opposite displacement of the pile body are recorded as first record data; and a pile top load box in the pile cap loading section is loaded, the upper pile body and the lower pile body are driven to deform oppositely, and at least the stress of the pile top load box and the opposite displacement of the pile body are recorded as second record data. The method for detecting the bearing capacity of the pile foundation is simpler, more efficient and quicker.

The invention relates to the technical field of geological exploration, and discloses a complex stratum high-precision vertical settlement observation deep hole drilling process which comprises the steps of stratum pretreatment and grouting reinforcement, real-time monitoring of the position and posture of a drill bit and optimization of drilling parameters, intelligent prediction of the drilling parameters through a machine learning algorithm, and deep hole drilling. Real-time monitoring of drilling tool and geological changes and parameter adjustment, fault identification and processing suggestion, drilling quality inspection, wall surface strengthening treatment, and long-term monitoring and maintenance based on the Internet of Things; according to the technology, the drilling precision, efficiency and safety are improved, long-term stability of the drilling quality is ensured, through drill bit positioning and track optimization, the positioning precision is improved, the position and track of the drill bit can be predicted more accurately, errors are reduced, drilling parameters can be adjusted in real time according to the stratum characteristics, and the drilling efficiency is improved; by optimizing the drill hole wall surface strengthening treatment technology and process parameters, the stability and bearing capacity of the drill hole wall surface can be enhanced, and the risks of collapse and deformation of the drill hole are reduced.

The invention discloses an offshore inserting and pulling pile area foundation repairing method and system based on soil gradation optimization, and relates to the technical field of foundation repairing. The method comprises the steps that disturbed soil and undisturbed soil samples of an offshore inserting and pulling pile construction area are collected, a soil combination mode of a disturbed area is established, and soil of the disturbed area is configured; the total bearing capacity requirement and the pile shoe mud entering depth of the mobile platform are obtained, and the pile pitching bearing capacity requirement is calculated; with the pile pitching bearing capacity requirement as an optimization target, a bearing capacity evaluation function is configured, optimization analysis of filler grading is carried out, and an optimization analysis result is established; and the filler proportion and the particle mixing mode are controlled according to the optimization analysis result, and offshore pile inserting and pulling area foundation repairing is completed through the layered backfilling and vibration compaction technology. The technical problem that in the prior art, pile sliding and other potential safety hazards exist in a platform due to the fact that the strength of well site disturbed soil is reduced due to repeated pile inserting and pulling construction is solved, and the technical effects of improving the foundation mechanical property of a disturbed area and guaranteeing safety and stability of platform operation are achieved.

The invention relates to the technical field of quality tracing of cast-in-place piles, in particular to a quality tracing method and system for cast-in-place pile construction. The method comprises the following steps that geological information of an area where the cast-in-place pile is located is obtained by obtaining geographic position data of the cast-in-place pile and conducting geological condition detection; the terrain complexity of the area where the cast-in-place pile is located is estimated, the fracture probability is calculated according to the cast-in-place pile design data and the terrain complexity data, and the stability of the pile foundation is evaluated; the method comprises the following steps: analyzing fracture probability data, detecting attenuation of pile foundation bearing capacity, calculating the collapse probability of a cast-in-place pile, tracing the construction quality according to the collapse probability of the cast-in-place pile and terrain complexity data so as to track factors influencing the construction quality, and determining the construction quality of the cast-in-place pile by combining quality tracing data with design risk assessment data. And the design of the cast-in-place pile is optimized. According to the method, the design of the cast-in-place pile is optimized, so that the cast-in-place pile construction is safer and more perfect.

The invention provides a plate anchor ultimate bearing capacity calculation method and device. The method comprises the steps that soil body strain softening, anchor plate geometry and ocean clay initial mechanical parameters are obtained; the method comprises the following steps: constructing a Drucker-Prager elastic-plastic numerical model based on a Cosseerat continuum theory; calculating bearing capacity under different burial depth ratios, inclination angles beta and softening moduli; determining a burial depth ratio demarcation threshold value; constructing a burial depth and dip angle coupled reference bearing capacity formula, which is divided into burial depth ratio lt; 4 and > = 4, respectively using quadratic polynomial and linear regression analysis; constructing a strain softening correction coefficient formula, and fitting in two working conditions; and generating a comprehensive ultimate bearing capacity empirical formula in combination with the reference formula and the correction coefficient formula. According to the method, the rotational degree of freedom and the bending moment balance item are introduced, the grid dependence is reduced in combination with the characteristic length parameter, the comprehensive empirical formula is constructed through large-scale parameterized numerical calculation, and the prediction error is effectively reduced.

The invention provides a precast pile, a combined pile and a construction method, and relates to the technical field of pile foundation construction.The precast pile comprises a first pile body, a second pile body and a third pile body, the first thickened protrusions are fixed to the peripheral wall of the first pile body and arranged in the length direction of the first pile body at intervals; the first annular protrusion is fixed to the first pile body in a surrounding mode, and the at least one first thickened protrusion is located between the first annular protrusion and the second end; when the precast pile is placed in the drill hole, the projection of the inner peripheral wall of the drill hole in the length direction of the first pile body surrounds the outer side of the projection of the combination body of the first pile body and the first thickened protrusion in the length direction of the first pile body, and the projection of the first annular protrusion in the length direction of the first pile body completely covers the projection of the inner peripheral wall of the drill hole in the length direction of the first pile body. After construction of the combined pile comprising the precast pile is completed, the bearing capacity of the combined pile can be improved.

The invention relates to the technical field of geotechnical engineering, and discloses a composite grouting system for wind power plant foundation reinforcement, which comprises a vehicle body, the bottom of the vehicle body is rotatably connected with a long shaft, the two ends of the long shaft are fixedly connected with rollers, the top of the vehicle body is fixedly connected with a storage tank, one side of the outer wall of the vehicle body is fixedly connected with a motor, and the motor is fixedly connected with the storage tank. The output end of the motor is fixedly connected with a spiral electronic scale, the input end of the spiral electronic scale communicates with the output end of the storage tank, the output end of the spiral electronic scale communicates with a grouting pump, the output end of the grouting pump communicates with the outside, and a grouting system is installed in the vehicle body. The grouting pressure and the grouting flow are controlled through the grouting pumping module, so that stratum gaps are fully filled with grout, the compactness and the bearing capacity of a foundation are improved, the stability of the grouting flow is guaranteed, the problems that the grout blocks a pipeline or the pressure fluctuation is too large are solved, and the continuity and the safety of grouting construction are guaranteed.

The invention discloses a large-span stiff skeleton arch bridge skewback foundation mass concrete crack control method, and relates to the technical field of bridge engineering, and the system comprises the following components: S1, building a collaborative analysis model, S2, analyzing deformation influence, and S3, implementing crack control measures. The method has high pertinence and practicability by adjusting the concrete mix proportion, adding the admixture, setting temperature control measures and optimizing the reinforcement design, the concrete mix proportion and the cement dosage can be adjusted in a targeted mode through the concrete stress distribution condition and the stiff skeleton deformation condition obtained through the collaborative analysis model, and the construction efficiency is improved. The additive is added to reduce the adverse effect of hydration heat, meanwhile, effective temperature control measures are set according to the temperature field distribution condition, in addition, by optimizing the reinforcement design, the bearing capacity and crack resistance of the skewback foundation can be further improved, the crack risk of large-size concrete of the skewback foundation of the large-span stiff skeleton arch bridge is effectively reduced, and the service life of the large-span stiff skeleton arch bridge is prolonged. And the overall quality and safety of a project are improved.

The invention discloses a narrow foundation pit upheaval resistance stability calculation method, which comprises the following steps: acquiring actual length, width and depth dimensions of a foundation pit and a consolidation undrained strength index, cohesion ccu and an internal friction angle phi cu of a field soil layer, and calculating a type critical width according to an improvement formula considering the internal friction angle of soil and a first width calculation coefficient, and whether the foundation pit is the narrow foundation pit or not is determined according to the comparison result of the actual foundation pit width and the type critical width. When the actual foundation pit is determined to be the narrow foundation pit, the width of a sinking soil body on the side face of the foundation pit is reversely solved through an improvement formula considering the internal friction angle of soil and the width of the actual foundation pit, and the upheaval-resistant stability coefficient of the narrow foundation pit based on the foundation bearing capacity mode is calculated and compared with the upheaval-resistant stability coefficient of the arc sliding mode. And taking the smaller value as the anti-upheaval stability coefficient of the narrow foundation pit so as to evaluate the anti-upheaval stability of the pit bottom of the foundation pit. Therefore, the problems that in the related technology, the judgment standard of the narrow foundation pit and selection of the slip plane are unreasonable, preconditions for checking calculation according to the narrow foundation pit design are unknown, and the friction angle in the stratum is not considered are solved.