8 results about "Strength reduction" patented technology

The invention relates to a rock-soil-building block collaborative slope reliability analysis method considering spatial variability. The method comprises the following steps: establishing a slope finite element model; aiming at the finite element model, constructing an autocorrelation random field which takes a soil mass parameter as a variable and has a discrete characteristic by using a Cholesky Decomposition midpoint method; coupling the self-correlation random field based on a Copula model to form a cross-correlation standard uniform random field, and performing equal probability conversion on the cross-correlation standard uniform random field to form a cross-correlation random field in logarithmic normal distribution; and inputting the generated random field into a finite element model, obtaining a safety coefficient by using a strength reduction method, and determining the slope reliability based on a Monte Carlo method. According to the method, the finite element analysis result is closer to the actual situation, and the accuracy of the reliability analysis result is remarkably improved.

The invention belongs to the field of structural engineering, and particularly relates to a concrete compressive strength calculation method considering a strain rate effect and a size effect. The concrete compressive strength formula considering the size effect and the strain rate effect at the same time is deduced from the size effect formula and the strain rate effect formula of the concrete compressive strength. The formula comprises a constant term, a strain rate effect term, a size effect term and an interaction term. The constant item reflects the static strength of the concrete cubic test piece, the strain rate effect item reflects the strength improvement caused by strain rate increase, the size effect item reflects the strength reduction effect caused by test piece size increase, and the interaction item reflects the strain rate effect increase caused by the size increase and the size effect reduction caused by the strain rate increase. And finally, fitting all test data by adopting a multiple regression method to obtain various parameters of the concrete compressive strength. The formula fitting effect is good, the regression residual error is small, and the adaptability of the calculation method is verified.

The application discloses a kind of based on deformation monitoring data's slope instability evaluation method, it is related to slope engineering monitoring data analysis field, method is: obtaining the related data such as topography, stratum, foundation monitoring point in the range around slope;According to the distribution of deformation foundation monitoring point and deformation fitting potential sliding surface;Establish three-dimensional finite element model of slope, and determine the cohesion and internal friction angle of potential sliding surface by inversion;The inversion cohesion and internal friction angle of sliding surface are calculated by strength reduction method, and the safety factor of slope is determined;According to the horizontal displacement direction of foundation monitoring point and potential unstable slope body, the sliding direction of slope is determined;Finally, the slope, potential unstable slope body and its sliding direction are displayed through visual platform, and the volume of potential unstable slope body and the safety factor of slope are displayed by text.The application determines the three-dimensional sliding surface of slope by surface fitting, and then calculates the safety factor of slope by parameter inversion and strength reduction method, realizes the early warning description of slope instability form including instability volume, direction and other characteristics.

The application discloses a kind of multi-line parallel pipeline jacking reasonable construction sequence design methods, using numerical calculation means, respectively calculate the stability safety factor K of different pipeline cover layer thickness H, different interlayer width D etc. ij Between different pipeline jacking sequence of the i-th working condition, compare the stability safety factor K of pipeline cavern ij Size, sequentially select the minimum value K ijmin Of each pipeline safety factor under the i-th working condition, compare the K ijmin Value size under different working conditions and select the maximum max [K ijmin ], the pipeline construction cavern max [K ijmin ] corresponding working condition under the pipeline construction jacking sequence of multi-line parallel pipeline is optimal jacking sequence.The application uses finite element strength reduction method to obtain the stability safety factor K of pipeline cavern, compares the stability safety factor K of cavern under different jacking sequence of working condition, and the pipeline construction jacking sequence with maximum safety factor is taken as the reasonable jacking sequence of pipeline construction under the working condition.

The application discloses a method for determining a filled wall constitutive model considering stiffness contribution, and relates to the field of finite element simulation, which comprises the following steps: establishing a five-section constitutive model of a diagonal bracing, determining the elastic modulus of the diagonal bracing, the tangent modulus of a strengthening section of the diagonal bracing, the corresponding secant modulus of the ultimate strain of the diagonal bracing, the ultimate strength of the diagonal bracing, the yield strength, the residual strength, the starting point strain corresponding to the ultimate strength of the diagonal bracing, and the end point strain corresponding to the ultimate strength of the diagonal bracing, correcting the ultimate strength of the diagonal bracing, the yield strength and the residual strength by using a strength reduction coefficient, and correcting the starting point strain corresponding to the ultimate strength of the diagonal bracing by using a starting point strain correction coefficient. The application can give material parameters of a simplified model corresponding to a wall body under the influence of different factors, and then accurately simulate the stiffness contribution of different wall bodies at different stages to the structure, so as to realize a structure modeling method considering the stiffness of the filled wall.

A method for analyzing the overtopping failure of earth-rock dams based on the material point method belongs to the field of numerical simulation technology in civil engineering and hydraulics. The steps are as follows: S1, read in the material point information for each zone, background mesh information, material constitutive models and parameters of the material points, load information of the material points, and related calculation parameters; S2, based on the material point adaptive mapping technique, update the position and momentum of the material points in each time step; S3, calculate the equivalent plastic strain of the material points, consider the fluid-solid transformation of the material points in the dam area through the strength reduction method, and update the stress of the material points according to the constitutive models of the material points in each zone; S4, repeat S2 and S3 until all time steps are completed, and output the deformation and reservoir water level changes at typical moments during the overtopping failure process of the earth-rock dam. This invention uses adaptive mapping to improve the computational efficiency of large-scale problems, effectively reflects the scouring effect of reservoir water on the dam slope during the overtopping process, and reasonably reproduces the evolution process of the overtopping failure of earth-rock dams.

The invention provides a slope support scheme evaluation method and system, and is suitable for the technical field of slope support. The method comprises the steps of index determination, index weight calculation, index scoring and comprehensive score calculation, and a comprehensive slope support scheme evaluation system is constructed by combining multi-dimensional indexes. Geotechnical parameters are dynamically adjusted by adopting a strength reduction method, a relation between slope crest displacement and a safety coefficient is fitted through an objective function, an optimization algorithm is started to accelerate convergence after a polynomial curve is generated by introducing pre-iteration, and the problems that time is consumed when multiple schemes are compared and selected, and safety coefficient calculation consumes much time are solved. A construction difficulty index and a surrounding environment-friendly degree index are quantified, and related parameters are input through a system for automatic scoring.

The application discloses a kind of deep stage cemented filling body strength calculation method considering mining and filling timing, comprising the following steps: S1, construct the three-dimensional finite element model of underground ore body mining and filling mining and filling timing process, numerical simulation calculation is carried out;S2, the displacement cusp mutation analysis function of typical measuring point is established by strength reduction method to determine the threshold value of total displacement and safety factor, and the rationality of threshold value is verified by the displacement nephogram and stress nephogram of finite element cemented filling body numerical model, qualitative analysis;S3, by column network discrete method, the three-dimensional analysis model of cemented filling body strength requirement is reconstructed, and the volume of cemented filling body fracture surface and failure area is determined according to the threshold value of total displacement and safety factor, and finally the strength required by cemented filling body is determined.The strength of filling body determined by the method is accurate and reasonable, effectively solves the problem of filling mining safety and economic balance, and is especially suitable for the strength requirement calculation of cemented filling body of deep stage open stope subsequent filling mining method.