51 results about "Critical load" patented technology

The invention discloses a power system cascading failure chain modeling and blocking method, device and system considering source-load double-end uncertainty, and a medium. The method comprises the steps of constructing source-load uncertainty input distribution (wind power introduces Weibull distribution based on a wind speed segmented power model, photovoltaic introduces Beta distribution based on an irradiance output model, and a load side introduces a normal distribution fluctuation model); an MSFF method is adopted to construct a unified source-load stochastic power flow model, and a multi-scene power flow state set is obtained; introducing a power flow out-of-limit criterion and a hidden fault probability function, building a cascading fault propagation model fusing wind-solar load uncertainty, and dynamically simulating fault chain evolution; and formulating a staged collaborative blocking strategy (cutting off non-critical load emergency control, quickly responding a battery energy storage system and dynamically adjusting a critical line protection constant value) to realize real-time fault suppression. Simulation shows that the method is suitable for power system security defense in a high-proportion new energy penetration scene, and has good engineering adaptability and dynamic control performance.

The invention discloses a low-temperature-impact-resistant high-strength bolt for a high-cold railway and a heat treatment method of the low-temperature-impact-resistant high-strength bolt. The bolt is of a special three-layer structure of a base body, a bionic nanometer laminated layer and a high-entropy alloy nitriding layer, wherein the grain size of the base body reaches the ASTM8 level or above; the bionic nano laminated layer is formed by alternately depositing TiN and VC, and the thickness of a single layer is less than 50nm; the high-entropy alloy nitriding layer is made of AlCoCrFeNiTi, the thickness is larger than 50 microns, the heat treatment method comprises the steps of grain refinement pretreatment, lamination preparation through magnetron sputtering, high-entropy alloy laser cladding, electromagnetic field assisted nitriding, oil quenching, cryogenic oscillation, tempering and the like, and intelligent quality control means such as a machine learning model, sound pressure feedback and image recognition are integrated. According to the scheme, the impact energy of the bolt at the temperature of minus 60 DEG C is higher than 55 J, the tensile strength is larger than 1200 MPa, the surface hardness is not lower than 1200 HV, the interface bonding critical load is higher than 80 N, and the problems of low-temperature brittle fracture, obdurability contradiction and quality consistency of the high and cold bolt are solved.

This invention discloses a method and system for collaborative power supply restoration of a distribution network using multiple emergency resources under disaster scenarios. The method includes: constructing a probabilistic fault model of the distribution network under disaster scenarios and pre-deploying multiple emergency resources, and performing active power supply islanding; initially locating faulty lines based on real-time data of the distribution network and verifying the location results in conjunction with the probabilistic fault model to form a final set of faulty lines; dividing faulty areas and performing fault isolation and temporary power supply topology reconstruction of non-faulty areas based on the active power supply islanding scheme; constructing multiple recovery subtree networks (RSNs) in the non-faulty areas and collaboratively optimizing the multi-emergency resource scheduling scheme; comprehensively evaluating the restoration effect, and if the evaluation is not up to standard, dynamically adjusting the RSN construction and resource scheduling scheme to form a closed-loop optimization. This invention, by constructing a full-process collaborative framework, integrates multiple emergency resources to achieve rapid and reliable restoration of critical loads, improving the resilience and power supply stability of the distribution network under extreme weather conditions.

The invention relates to the technical field of suspension bridge cable clamp detection, and particularly discloses a cable clamp anti-sliding performance detection method based on multi-point stress-strain monitoring, and the method comprises the steps: simulating a main cable through a full-scale sample, installing a test cable clamp and a brake cable clamp, and applying an axial thrust through a jack. A strain gauge, an axial force meter and a displacement meter are arranged on a cable clamp and a bolt, graded loading is carried out to obtain a bolt pre-tightening force attenuation curve and a slippage critical load, and therefore the friction coefficient mu is calculated. And establishing a main cable-cable clamp three-dimensional contact finite element model, and inputting mu and pre-tightening force attenuation data measured by the test to carry out simulation calibration, so that a simulation result is consistent with that of the test. And finally, a bolt is fastened to a design value in the calibrated model, and vertical sling force is applied to the sling clamp lug plate until the sling clamp lug plate slides, so that the maximum anti-sliding force of the sling clamp is obtained. The objective of the invention is to solve the problems that an existing cable clamp anti-sliding performance testing method excessively depends on a finished bridge main cable, the cost is high, the period is long, and matching verification cannot be carried out in the early stage of a project.

The invention provides a prediction method for dynamic buckling characteristics of a reinforced cylindrical shell with initial defects under an underwater explosion load based on artificial intelligence. The method specifically comprises the following steps: establishing a dynamic response characteristic three-dimensional numerical calculation model of initial defects of the reinforced cylindrical shell structure under an underwater explosion load; obtaining a rib and skin rigidity matching factor; calculating dynamic response characteristics of the reinforced cylindrical shell under different explosive equivalents, different explosion distances and different laying water depths; determining a dynamic buckling critical load and a buckling mode of the reinforced cylindrical shell under the underwater explosion load by combining a dynamic buckling criterion and annular and axial typical response characteristic space distribution characteristics; and establishing an artificial intelligence proxy model of the dynamic buckling characteristics of the reinforced cylindrical shell under the underwater explosion load. According to the method, different defect amplitudes and rib and skin rigidities under the underwater explosion shock wave and bubble pulsation coupling load can be rapidly given based on the proxy model, the dynamic buckling critical load and modality of the reinforced cylindrical shell under the water depth are laid, and the method has high practicability and engineering significance.

The invention relates to the technical field of oil exploration, and provides an analysis method and device for safe tripping-in of a well completion pipe string, and the method comprises the steps: obtaining the actual hook load data and well section information of an open hole section based on a drifting process; constructing a tubular column friction torque calculation model of the drifting drilling tool assembly; on the basis of the tubular column friction resistance torque calculation model, the actual hook load data of the open hole section and the well section information of the well, the well hole open hole section friction resistance coefficient is calibrated; on the basis of well section information and the well hole open hole section friction resistance coefficient, a solving model of the axial force of the well completion pipe string and a critical load value calculation model of well completion pipe string buckling are built; and on the basis of the solving model of the axial force of the well completion pipe string and the calculation model of the critical load value of buckling of the well completion pipe string, whether the well completion pipe string is safely tripped is determined. According to the method, the friction resistance coefficient in the drifting stage is determined, the invisible shaft cleaning state is known, the current friction resistance coefficient is used for evaluating the to-be-tripped well completion pipe string, and therefore operation risks and operation complexity are avoided, and the operation efficiency is improved.

This invention provides a method for improving the reliability of distribution networks during ice storms based on micro-meteorological sensing and multi-resource collaboration, relating to the field of distribution network disaster prevention technology. The method includes: simulating a distribution network fault sequence during the ice storm evolution process using Markov chains based on real-time ice storm data acquired during the ice storm and a pre-defined distribution network recovery plan; determining the expected value of critical load losses based on the distribution network fault sequence; generating a new distribution network recovery plan with the objective function of minimizing power supply loss if the expected value is greater than a preset risk threshold; estimating the transient impact intensity based on the new distribution network recovery plan; selecting target equipment whose regulation performance meets preset regulation performance standards when the transient impact intensity exceeds a preset safety limit, and using the target equipment to reduce the transient impact intensity; and executing the new distribution network recovery plan when the reduced transient impact intensity is less than the preset safety limit. This method reduces expected power outage energy losses and improves the power supply reliability of the distribution network during ice storms.

The present application belongs to the technical field of anti-cracking design of fiber reinforced concrete, and particularly relates to a mesoscale fiber reinforced concrete anti-cracking design method without size effect. A fiber reinforced concrete tensile strength prediction model without size effect is established based on a nonlinear mesoscale fracture theory. The present application innovatively proposes that the average fiber spacing is a dominant factor influencing the critical crack propagation length and the critical load at the macro and mesoscale levels of fiber reinforced concrete, reveals the whole process of cracking failure of fiber reinforced concrete, and further establishes a closed solution mesoscale prediction model of the tensile strength of fiber reinforced concrete without size effect. Compared with the prediction results of traditional models, the present application is more accurate, is applicable to geometrically similar and geometrically dissimilar specimens of different sizes, is simple to operate, can reduce the cracking risk of fiber reinforced concrete structures in combination with numerical simulation, and is conducive to engineering promotion and application.

The invention discloses a bridge two-dimensional over-limit partition monitoring and early warning and safety risk control method, device, equipment, medium and product, and relates to the field of bridge safety risk control, and the method comprises the steps: carrying out the bi-two-dimensional safety evaluation according to a finite element simulation value of a to-be-evaluated bridge structure state and a real bridge monitoring value, determining the technical condition and the evaluation grade of the to-be-evaluated bridge; determining a plurality of over-limit vehicle load grades based on bridge technical conditions and evaluation grades thereof; determining a load range corresponding to each over-limit vehicle load grade according to the vehicle critical load in the normal use limit state and the bearing capacity limit state; based on this, determining a load upper limit corresponding to the current structure state; and according to the determined load upper limit, determining a current over-limit vehicle load grade from the plurality of over-limit vehicle load grades so as to determine a current early warning grade and a current safety risk control measure, and carrying out early warning and safety risk control on the to-be-evaluated bridge. According to the invention, quantitative evaluation of the bridge safety risk is realized.

This invention discloses an optimization method for restoring power supply to critical loads in active distribution networks based on user outage loss assessment. The method includes the following steps: collecting user outage time, duration, and economic and social loss information; establishing a quantitative model of outage loss; using the results of the outage loss model, combined with the grid topology and restoration difficulty, comprehensively evaluating and prioritizing loads to generate a critical load sequence; constructing a power restoration optimization model with the goal of minimizing outage loss; applying the optimization strategy to actual distribution network operation; collecting restoration effect data; dynamically adjusting; and forming an iterative optimization. This invention not only achieves critical load identification and prioritization based on user outage loss, enabling priority restoration of loads with the greatest economic and social impact under limited resources, but also significantly improves the restoration efficiency and scientific nature of power supply decisions in active distribution networks after sudden power outages, balancing power supply security, economy, and social benefits.

This invention proposes an intelligent prediction method for performance degradation and durability limit state assessment of reinforced concrete structures, comprising: establishing a probabilistic model of random variables for environmental and structural parameters; constructing an intelligent prediction model for chloride ion diffusion by fusing convolutional neural networks, and using Monte Carlo sampling analysis to analyze the probability distribution of the initial corrosion time of the reinforcing bars to predict the depassivation time of the reinforcing bars; establishing a time-varying corrosion model of the reinforcing bars to obtain the change of the corrosion loss rate of the reinforcing bars over time; further, using an incremental static analysis method, establishing a multi-scale finite element model of the reinforced concrete structure under different corrosion rate conditions through random sampling; obtaining the critical load value under the limit state to obtain the failure probability curve under different corrosion degrees; and finally, by defining a bearing capacity reduction coefficient, obtaining the bearing capacity failure time of the reinforced concrete structure to achieve the durability limit state assessment of the reinforced concrete structure under corrosion.

The invention belongs to the technical field of ships, and discloses a testing method for a PCTC ship stern ramp load monitoring system, the theoretical maximum load capacity of a stern ramp in the non-starting state of the stern ramp load monitoring system is Wmax1, the theoretical maximum load capacity of the stern ramp in the starting state of the stern ramp load monitoring system is Wmax2, and the theoretical maximum load capacity of the stern ramp in the starting state of the stern ramp load monitoring system is Wmax2. Comprising the following steps that a starting button of a stern ramp load monitoring system is pressed down, a stern ramp is opened, and the included angle between the stern ramp and the wharf ground is smaller than or equal to 6 degrees; a weight-free load test is carried out; carrying out load testing within Wmax1; a load test of a Wmax1 critical value is carried out; a load test of a Wmax2 critical value is carried out; compared with the mode that a crane is used for hoisting the weights one by one and the module vehicle loads and moves the weights, crane resources are saved, the testing efficiency is greatly improved, the influence of testing on the wharf production period is reduced, the influence of water level changes caused by tide rising and tide falling on testing is reduced, and the reliability of testing results is improved.

The invention provides a lateral buckling detection device for a steel belt of a flexible connecting piece and a detection method of the lateral buckling detection device, and relates to the technical field of lateral buckling detection of steel belts. The steel belt is wound on the outer wall of the inner cylinder and limited in the annular space between the inner cylinder and the outer cylinder, the first end of the steel belt is fixed to the bottom plate, the second end of the steel belt is fixed to the driving assembly, and the driving assembly enables the steel belt to bend laterally; the monitoring assembly is used for acquiring first image information, second image information, first data information and second data information of the steel belt in real time, and the calculation unit is used for determining the buckling form of the steel belt according to the first image information and the second image information and determining the buckling critical load of the steel belt according to the first data information and the second data information. According to the technical scheme, the lateral buckling behavior of the steel belt can be accurately reproduced, miniaturization and precision of the detection device are achieved, and a visual whole-process dynamic monitoring means is provided for revealing the lateral buckling evolution mechanism of the steel belt in the limited space.

The invention provides a method and system for determining the thickness of an intrinsic crack, computer equipment and a medium, and belongs to the field of crack-containing structure fracture performance evaluation.The method comprises the steps that a real stress-strain curve and a tensile strength value of a sample material are obtained; the method comprises the following steps: processing a material into a sample containing a crack structure, applying a slowly increasing I-type load, and collecting a real critical load value at the moment of fracture; constructing a crack geometric model matched with the crack structure sample, presetting an initial intrinsic crack thickness and importing material performance data; applying the same I-type load to the model, and calculating the maximum principal stress of the crack tip in real time; the intrinsic crack thickness value is circularly adjusted, and when the error between the tip stress and the tensile strength and the error between the simulated fracture load and the real critical load meet the preset standard, the optimized intrinsic crack thickness is the intrinsic crack thickness of the characterization material; according to the method, the fracture performance of the crack-containing structure can be accurately evaluated by establishing a method for measuring the thickness of the intrinsic crack in an actual material.

The application discloses a buckling-restrained design analysis method for a steel lining anchoring system, which comprises the following steps: obtaining a node force balance equation based on a steel lining plate constitutive relation and a bolt constitutive relation; obtaining node displacement data based on the node force balance equation, and obtaining strain value data based on the node displacement data; obtaining actual node force of the steel lining plate based on the strain value data and the steel lining plate constitutive relation, and obtaining actual node force of the bolt based on the node displacement data and the bolt constitutive relation; obtaining node force residual based on the node displacement data, the strain value data, the actual node force of the steel lining plate and the actual node force of the bolt; if the node force residual is greater than a threshold value, updating the node displacement data and the strain value data, and continuing to calculate the node force residual until the node force residual is less than the threshold value. The method realizes accurate calculation of a buckling critical load of the steel lining, and provides theoretical support for a containment structure design of a nuclear power plant.

Specifically, the application discloses a multi-stage protection method for an intelligent safety rope for power aerial work, and belongs to the field of intelligent safety, and comprises the following steps: S1. Assembling a main bearing rope body, a companion constraint rope body, an anchor point assembly, a sliding modulation assembly, a segmented locking assembly, a human body connecting assembly and a distributed sensing unit along the rope before work, and establishing an initial stress configuration; S2. Collecting state parameters of the main bearing rope body, the anchor point assembly and the human body connecting assembly during work, and forming a three-level state set; S3. Adjusting a stress path of the main bearing rope body, a state of the companion constraint rope body and a stress center of the human body connecting assembly before a critical load is applied; S4. Sequentially performing segmented locking, sliding energy dissipation, shunt bearing and rigid limiting in an impact stage; and S5. Generating a load history after impact and completing review and retirement. The method has the beneficial effects of improving the protection reliability and impact control capability in power aerial work.

The invention provides a preparation method of a high-temperature-resistant composite lubricating film in a vacuum environment, and relates to the technical field of functional materials. Through a magnetron sputtering process, a titanium (Ti) transition layer is deposited on the surface of a metal substrate, and silver (Ag) layers and molybdenum disulfide (MoS2) layers are sequentially and alternately deposited on the surface of the transition layer. Through the gradient heterojunction constructed through interface engineering, the bonding strength between the thin film and the metal matrix is remarkably improved, and the scratch critical load is 30 N or above. Under the severe working condition of 300 DEG C in vacuum, the material shows an ultralow friction coefficient (less than 0.15) and a wear-resistant life gt; 5 * 10 < 5 > r. The lubricating oil is particularly suitable for long-life lubrication of a key kinematic pair of a high-temperature transmission mechanism of a spacecraft.

The invention discloses a variable cross-section arc arch rib out-of-plane instability critical load calculation method and system, and the method comprises the steps: building an axial and radial control equation of a variable cross-section arc arch based on an out-of-plane instability analysis model of the variable cross-section arch under the action of a uniformly distributed radial load; solving the axial and radial control equations of the variable cross-section arc arch through a harmonic differential quadrature algorithm to obtain an in-plane dimensionless displacement matrix of the arch under unit load set; based on the out-of-plane instability state of the variable cross-section arc arch, an out-of-plane control equation is constructed and solved, and an out-of-plane instability critical load matrix of the variable cross-section arc arch is obtained; and the out-of-plane instability critical load calculation of the variable cross-section arc arch rib is realized. The method can be suitable for various in-plane and out-of-plane boundary conditions and variable cross-section working conditions, and the calculation precision of the out-of-plane instability critical load of the variable cross-section arc arch rib is improved. The method and the system for calculating the out-of-plane instability critical load of the variable cross-section arc arch rib can be widely applied to the technical field of bridge design.

1. The name of the design product: multi-power automatic switching protector (LN isolation type). 2. The use of the design product: to ensure that critical loads can automatically switch to backup power when the power fails, thereby maintaining the normal operation of the equipment and avoiding production interruption and equipment damage due to power failure. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: perspective view.

This invention discloses a variable contact rolling-sliding composite bearing and its design method, relating to the field of bearing technology. The bearing includes an outer ring, an inner ring, bearing rollers, and a cage. The diameter of the bearing rollers is larger than the axial height of the cage to form an initial clearance. When the external load is small, the bearing rollers bear the load alone, and the bearing is in a pure rolling contact state. When the external load increases to the point that the bearing rollers undergo elastic deformation and the initial clearance closes, the end face of the cage contacts the raceway surface of the outer ring, sharing the load with the bearing rollers, and the bearing switches to a rolling-sliding composite contact state. The design method involves: calculating the roller deformation to determine the critical load; establishing a spring stiffness model for the rollers and cage to solve for the load distribution; checking whether the cage contact stress is lower than the yield limit; if it exceeds the limit, increasing the initial clearance and iteratively optimizing. This invention achieves adaptive switching of the bearing's operating mode, enabling low friction under light loads and high load capacity under heavy loads, and the design method is universal and reliable.

The invention discloses a double-sided non-equal-curvature corrugated pressure-resistant shell and a rolling forming device and method, and belongs to the technical field of deep sea equipment pressure-resistant structure design and metal plastic forming. The double-sided non-equal-curvature corrugated pressure-resistant shell comprises a corrugated shell body, the inner surface and the outer surface of the corrugated shell body are each provided with a circumferential corrugated shape, and the wave crest area is a negative Gaussian curvature shell section; the wave trough area is a positive Gaussian curvature shell section, the inner surface corrugation amplitude is larger than the outer surface corrugation amplitude, the thickness of the corrugated shell body periodically and continuously changes in the axial direction, no thickness sudden change exists, the thickness at the wave crest is the maximum value, and the thickness at the wave trough is the minimum value. The problem that the corrugated pressure-resistant shell cracks and loses efficacy before reaching the critical load can be solved, the buckling mode is improved, the buckling load is improved, and the light weight of the shell is promoted.

This application discloses a method, apparatus, device, and storage medium for determining the critical load of a thin film. This application determines the total input energy load curve through a thin film scratch test. Based on the instantaneous normal load and total input energy in the initial stage of the scratch test, a baseline energy load curve for the entire stage is determined. Then, the failure energy load curve is determined using the energy balance method. This application performs first-order differentiation on the failure energy load curve and finds the peak value of the first-order derivative curve to determine the critical load of the thin film. This method eliminates the subjectivity of manual observation and the ambiguity of friction curves, greatly improving the repeatability of the results. Furthermore, this method eliminates the need to calculate cracking energy and peeling energy separately, avoiding the physical difficulties of directly calculating cracking energy and peeling energy. The peak value of the first-order derivative of the failure energy load curve more accurately corresponds to peeling in adhesion failure, thus the critical load can be accurately determined based on the peeling point.

The application discloses a SiC / SiC composite material water-oxygen corrosion system and a testing method, and belongs to the field of ceramic matrix composite material high-temperature environment damage testing and interface performance characterization. The water-oxygen corrosion system comprises a gas supply unit, a humidification unit, a gas mixing unit, a flow control unit, a high-temperature corrosion furnace, a sample bearing unit, a tail gas exhaust unit and a control monitoring unit; the sample bearing unit bears the sample in an edge support mode, so that the contact area is minimized. The testing method comprises the following steps: sample pretreatment, water-oxygen corrosion treatment, test section preparation, fiber push-in testing, interface initial debonding critical load determination, interface shear strength calculation and result analysis and evaluation. The application can stably control the high-temperature high-water-vapor-pressure corrosion environment, and quantitatively characterize the interface shear strength of the fiber / matrix after corrosion through nanoindentation fiber push-in testing, thereby solving the problems of unstable corrosion environment control, unreasonable sample support and difficult quantitative testing of the interface bonding state after corrosion in the prior art.

A steel ball extrusion deformation accurate measurement method for bearing rated static load determination comprises the following steps: selecting a plurality of steel balls with the same batch and consistent size, and assembling the steel balls in series in a special clamp along the axial direction to form a uniform stress system; applying an axial extrusion load through a testing machine, and acquiring an image sequence with a high-contrast characteristic mark by using a clamp observation window in cooperation with an industrial camera; adopting a sub-pixel-level feature tracking algorithm to extract the overall deformation of multiple steel balls, and based on the deformation consistency hypothesis of the steel balls connected in series, distributing the total deformation in equal proportion according to the number of the steel balls to obtain the contact deformation of the single steel ball; and the critical load corresponding to one-ten-thousandth-diameter plastic deformation is positioned in combination with load data, and core parameters are provided for determining the rated static load of the bearing. According to the invention, the measurement resolution is improved by 5-15 times through a series amplification effect, the precision reaches 0.01 [mu] m in cooperation with vision measurement, the deformation consistency is ensured by a special clamp, the bottleneck of micro deformation measurement is solved, and the device is adaptive to a conventional test scene of the bearing steel ball, and is low in cost and convenient to operate.

The application belongs to the technical field of I-beam cross-section structure parameter design, and particularly relates to an I-beam cross-section structure parameter design method, which comprises the following steps: determining structure design parameters of an I-beam cross-section; calculating a cross-section area of the I-beam based on the structure design parameters; calculating a critical load of compression instability of the I-beam based on the structure design parameters; designing constraints among the structure design parameters and designing a cross-section area constraint, and finding structure design parameters that maximize the critical load of compression instability of the I-beam.

The invention relates to the technical field of industrial control, and discloses a fault-tolerant water-cooling refrigeration station system optimization control method based on a large model, and the method comprises the steps: firstly building a pipe network hydraulic resistance topological model, traversing all single-pipe failure working conditions to calculate the equivalent hydraulic impedance from a cold source to a tail end, and carrying out the fault-tolerant control of the pipe network hydraulic resistance topological model; an impedance value under the most unfavorable working condition is extracted to construct a fault-tolerant hydraulic bottleneck parameter set; then, the parameter set is mapped into a whole network topology constraint vector, and the whole network topology constraint vector is combined with real-time flow data to be input into a pre-trained time sequence attention neural network model; the model fuses topological constraints into time sequence deduction by using an attention mechanism, and directly predicts a water supply and return pressure difference set value meeting a potential fault safety boundary. According to the method, the problem of system paralysis caused by insufficient safety margin when a pipe network suddenly breaks down in a traditional control strategy is effectively solved, and the continuity of key load cooling and the economical efficiency of system operation are guaranteed.

This invention relates to the field of metal fatigue prediction technology, and particularly to a method, apparatus, device, and computer-readable storage medium for rapid prediction of the entire fatigue life of additive metals based on damage and fracture. The method includes: acquiring the three-dimensional geometric parameters of internal void defects; calculating the porosity of each critical defect edge to obtain the critical load of the void defect; introducing an equivalent crack surface at the original defect location and calculating the equivalent initial crack length using a damage constitutive model; employing a semi-analytical crack propagation algorithm to calculate the propagation process of surface cracks, embedded cracks, and corner cracks in the component, obtaining the crack propagation life, and defining the shortest crack propagation life as the final structural fatigue life. The damage constitutive model fully considers the damage evolution and load coupling effect of defects, and the semi-analytical crack propagation calculation method, combined with an acceleration algorithm and crack conversion mechanism, significantly improves computational efficiency, meeting the rapid assessment needs in practical engineering.

The application discloses a casing running passability prediction method and device, and relates to the technical field of data processing. The application comprises the following steps: acquiring drilling data corresponding to each measuring point included in a target open hole section; calculating casing axial force, mechanical resistance value and comprehensive friction resistance value corresponding to each measuring point according to the drilling data corresponding to each measuring point and a modified mechanical model; calculating casing running safety factors corresponding to each measuring point according to the mechanical resistance value and the comprehensive friction resistance value corresponding to each measuring point; calculating sine buckling critical load and helical buckling critical load corresponding to each measuring point according to the drilling data corresponding to each measuring point; and determining a casing running passability prediction result corresponding to the target open hole section according to the casing running safety factors, the casing axial force, the sine buckling critical load, the helical buckling critical load and the comprehensive friction resistance value corresponding to each measuring point.

The embodiment of the present application provides a near-horizontal thin-layered stratum underground cavern vault collapse prediction method, a mechanics model is constructed based on an elastic thin plate theory, the length a of a stable layer rock plate and the critical stress sigma of a stable layer rock plate boundary are calculated through collected data crvx , and the stable layer height H is finally determined; a mechanics model is constructed based on a cantilever beam theory, the vertical force borne by each layer of rock plate in a collapse layer from an overlying rock mass and the temporary load when the fracture starts to occur are calculated through the thickness of each layer of rock plate in the collapse layer; the fracture length is calculated based on the vertical force borne by each layer of rock plate in the collapse layer from the overlying rock mass and the critical load when the fracture starts to occur; and the collapse amount is calculated through the fracture length and the stable layer height H. The present application provides a basis for determining the support control parameters of the near-horizontal layered stratum underground cavern, and ensures the stability of the surrounding rock of the underground cavern.

The invention mainly relates to the field of foundation bearing capacity calculation, in order to calculate a critical load p1 / 4 closer to an actual situation, the invention provides an improved method for calculating the critical load of a foundation under a strip-shaped foundation, and the core of the improved method is as follows: supposing that a static lateral pressure coefficient K0 of foundation soil is not equal to 1, obtaining a simplified Mohr-Coulomb strength criterion formula, enabling the buried depth z of the foundation soil under the foundation to be equal to b / 4, and calculating the critical load p1 / 4 of the foundation soil under the strip-shaped foundation; the method comprises the following steps of: performing decoupling with an elastic theory based on soil stress distribution under the strip-shaped foundation to obtain an expression of a base load p0 relative to an included angle difference value beta between one point in the foundation and the left edge and the right edge of the strip-shaped foundation to a drooping line under a critical load condition, and fitting beta in a value range of beta to obtain a base load p0 value; and replacing a trigonometric function term of the base load p0 with respect to beta under the critical load condition with a quadratic function term with respect to beta, solving beta, and substituting the solved beta into an expression of the base load p0 with respect to beta under the critical load condition to obtain a calculation formula of the critical load.