46results about How to "Mechanics concept is clear" patented technology

The invention provides a geostress field distributed data management (DDM) retrieval method based on actual measurement results and a linear programming method. According to the geostress field DDM retrieval method based on the actual measurement results and the linear programming method, required parameter information is obtained through experiments according to an engineering site geological exploration report, a displacement discontinuous method DDM numerical model is built according to the obtained information, gravity load is exerted in the vertical direction, unit load is exerted in the horizontal x direction, unit load is exerted in the horizontal z direction, an area stress field is obtained through DDM processing, stress data processing values of ground stress actual measuring points are extracted, processing regression coefficients corresponding to each working condition is processed with the linear programming method according to the stress data processing values of each ground stress actual measuring point, combining the stress field obtained by processing each working condition according to regression coefficients, and then summation is carried out to obtain an inversion ground stress field.

The invention discloses a calculation method of safety thickness of supporting layers of pile foundations of karst areas. The calculation method comprises the following steps: step 1, establishing an assumed model, and simplifying the model; step 2, performing theoretical analysis on the safety thickness of the supporting layers; step 3, performing preliminary checking calculation on the safety thickness of the supporting layers; step 4, performing accurate checking calculation on the safety thickness of the supporting layers; step 5, judging whether the supporting layers satisfy calculation requirements. The calculation method disclosed by the invention is simple in calculation, facilitates design optimization of pile foundations, and is high in operability; in addition, through the adoption of the calculation method, the improvement of relevant norms is promoted, so that huge economic benefits and social benefits can be brought.

The invention provides a bridge deflection detection method comprising the following steps that a. multiple inclination angle values corresponding to multiple specified points on a bridge are acquired; b. fitting of an inclination angle function f(x) is performed based on the multiple inclination angle values; and c. a deflection value I of a point to be detected is acquired according to the formula (which is expressed in the specification), wherein the interval [a, b] is an interval formed by the initial point of the inclination angle function and the point to be detected. The cross section inclination angle values measured by an inclinometer are processed by adopting an immediate integration method so that the mechanical concept is clear, the method is easy and convenient, the accuracy is better than that of a least square method, and other bridge information is not required apart from the cross section rotating angle and the cross section position.

The invention belongs to the technical field of bridge structural engineering, and in particular relates to a damaged prestressed concrete flexural member decompression moment test method. A damaged prestressed concrete flexural member decompression moment test system adopted by the method comprises a bridge, a vertical load applying device, a surface strain gauge and a data acquisition instrument, wherein the vertical load applying device is arranged on a to-be-detected cracking section of the bridge; the surface strain gauge is installed on the surface of outer edge reinforcement without reinforcement cover concrete at a tensile area of the to-be-detected cracking section of the bridge; the data acquiring instrument is connected with the surface strain gauge through a conductor. Compared with the prior art, the damaged prestressed concrete flexural member decompression moment test method is simple to operate, accurate and reliable in result, easily mastered by engineering technicians, and is suitable for detecting and evaluating the cracked prestressed concrete flexural member decompression moment.

The invention discloses a device and method for in-situ testing of an earth pressure. The device for in-situ testing of the earth pressure comprises a back panel, wherein the front face of the back panel is provided with a groove, an elastic contact panel is packaged and arranged on an open surface of the groove, and the elastic contact panel and the groove are enclosed to form a closed hydrauliccavity; and the hydraulic cavity is communicated with a hydraulic pressure meter, and the hydraulic cavity is filled with liquid. The device and the method provided by the invention have the advantages that the earth pressure is measured by adopting a hydraulic conduction mode, the influence of surrounding soil layers in a mounting process is small, and the problem that a measurement result is distorted in the prior art is effectively solved.

The invention relates to a structure for preventing a bridge from overturning transversely and a construction method of the structure and belongs to the technical field of bridge structures. The structure comprises bridge deck slab bottom embedded steel plates, channel steel plates, corbels, steel anchor rods and nuts. The corresponding steel plates are embedded in the bottom of a bridge deck slab along the two transverse sides and firmly connected with the bridge deck slab through anchoring parts. The channel steel plates and the embedded steel plates are connected in a welded manner. The steel corbels or the reinforced concrete corbels are arranged at the positions, close to the top, of a pier. Oval holes are reserved in the bottoms of the channel steel plates and the corbels. The diameter of each steel anchor rod is smaller than the width of each oval hole. The steel anchor rods vertically penetrate the reserved holes. The two ends of each steel anchor rod are screwed through the nuts. Tiny gaps are reserved between the nuts at the lower ends and the bottom faces of the corbels, so that a bridge deck system is allowed to slide freely in the longitudinal direction of the bridge, and meanwhile the bridge deck system and the pier can be connected in a pulling manner. The structure for preventing the bridge from overturning transversely is reasonable in stress, capable of obtaining materials easily, simple, convenient to construct, economical and practical.

The invention discloses a method for quickly extracting mid-span displacement influence lines of vehicles slowly passing through a simply supported beam bridge, and belongs to the technical field of bridge detection methods. The objective of the invention is to solve the problems of unclear mechanical concept and difficulty in obtaining an influence line measured value in an existing quasi-staticload test. According to the method, effective separation is carried out on a midspan displacement curve actually measured on site, the midspan displacement curve is compared with a theoretical influence line, quick evaluation work of the technical state of the bridge can be achieved, and the technical problem that in the quasi-static load test process, a theoretical value is not easy to obtain during data processing, and consequently the theoretical value cannot be compared with an actually-measured value can be effectively solved. The bridge state quick evaluation method based on the displacement influence line is clear, and the mechanical concept is clear; by means of the method, the displacement curves under the action of the multiple axles can be quickly converted into the structure influence lines, the structure influence lines can be directly compared with theoretical values, the operability of the method is improved, and then quick and accurate evaluation of the bridge state isachieved.

The invention discloses an optimized design method for the section of a multi-rib type T-shaped beam bridge. The optimized design method includes the steps that a governing differential equation and the natural boundary condition of the multi-rib type T-shaped beam bridge are built on the basis of the principle of minimum potential energy, influences of factors such as the shear-lag effect, the shear-lag warping stress self-equilibrium condition and Timoshenko shear deformation of the multi-rib type beam bridge are comprehensively considered to carry out fine mechanical analysis on the structure, and then the reasonable size of the section is selected to enable the multi-rib type beam bridge to be in the good mechanical state. According to the optimized design method, the mechanical analysis is more accurate, bad diseases such as beam cracks and rigidity reduction can be easily avoided accordingly, and the safety performance of the multi-rib type beam bridge is improved. The optimized design method is clear in mechanical concept and simple in calculation, the multi-rib type beam bridge is in the good operation state, and therefore the good application value is achieved.

The invention discloses a simply supported steel box girder prestressing cable shape optimizing method. By introducing a thin-walled box girder theory, the method is more accurate in mechanical analysis; compared with a traditional prestressing cable shape, the dual effects of obtaining pre-camber and exerting prestress can be well achieved. Due to the arrangement of optimized prestressing cables, a box girder is in a better mechanical state, and therefore bad damage such as girder box cracks and local instability can be easily avoided, and the durability of the structure is improved. Meanwhile, the method is clear in mechanical concept, simple in calculation and wide in application prospect and practical value. By means of the method, the mechanical performance of the box girder can be optimized, and the steel material consumption can be further saved.

The invention discloses a method for calculating a combined action of load structures under an internal water pressure of a composite lining of a shield tunnel. The method comprises the following steps of (1) building a calculation model for a lining, a shield segment and a surrounding rock which are arranged in sequence from inside to outside and bear the internal water pressure together, decomposing the lining, the shield segment and the surrounding rock into structure bodies bearing the internal water pressure separately, and calculating inner diameter changes of the structure bodies underthe action of different internal water pressures and relationships between the different internal water pressures and the stresses of the structure bodies; and (2) according to radial deformation coordination and deformation required to be controlled for seepage prevention, and in combination with a result in the step (1), determining loads sharable for the lining, the shield segment and the surrounding rock, and finally determining an actual structure of the shield tunnel under the condition of ensuring a bearable designed internal water pressure value, wherein a total internal water pressurebearable for the shield tunnel is a sum of internal water pressures bearable for the structure bodies under displacement coordination. According to the method, a mechanical concept is definite; the calculation is simple and convenient; and an effective, simple and convenient load structure method-based practical calculation method can be provided for engineering design of a complex stress structure.

The invention discloses a method for quickly extracting midspan displacement influence lines of a double-axle vehicle slowly passing through a continuous beam bridge, and belongs to the technical field of bridge detection methods. The method for quickly and accurately evaluating the state of the continuous beam bridge based on the displacement influence line is defined, the displacement curve under the action of the double-axle vehicle is quickly converted into the structure influence line, the structure influence line can be directly compared with a theoretical value, the operability is improved, and the mechanical concept is clear. According to the method, the midspan displacement curve actually measured on site is effectively separated and compared with the theoretical influence line, and then rapid evaluation work of the technical state of the bridge can be achieved. By means of the method, the technical problem that in the quasi-static load test process, theoretical values are noteasy to obtain during data processing, and consequently the theoretical values cannot be compared with measured values can be effectively solved.

The invention discloses an optimization method based on dynamic characteristic I-shaped beam section design. The method comprises the steps that deformation potential energy and kinetic energy of an I-shaped beam bridge are obtained at first, then, an energy variation method is utilized for obtaining a governing differential equation and natural boundary conditions of I-shaped beam vibration, a relevant application program is compiled based on this, and fine analysis is carried out on natural vibration characteristics of the structure through Matlab software; finally, the inherent frequency value of the I-shaped beam bridge is used as the criterion, in other words, the inherent frequency value is large, structure deformation potential energy is small, and the I-shaped beam section size is optimal, and the effectiveness of the method is further proved through the structure statics analysis. Due to the fact that mechanical analysis is accurate, the I-shaped beam bridge with the optimized section size is in a good mechanical state, and defects such as beam cracking, stiffness degradation and midspan excessive downwarping can be avoided. The optimization method is clear in mechanical conception and simple in calculation, has a good application value, and is the beneficial supplement for an existing I-shaped beam bridge design theory.

The invention discloses an intelligent steel strand tension value correction and calculation method with a grating embedded in a core wire, which comprises the following steps of: carving a groove in the core wire of a steel strand, embedding the grating, connecting one end of an optical fiber to the grating, and leading an interface at the other end of the optical fiber to the end part of the steel strand; calculating a strain iteration initial value and a strain iteration final value of the winding wire of the same section according to the parameters of the steel strand before being stressed, the corresponding parameters after being stressed, the strain monitoring result of the core wire of the steel strand in the structural stress process and the actual strain of the winding wire; and calculating the actual tension of the steel strand at the measuring point. The steel strand tension value correction calculation method provided by the invention is clear in mechanics concept, simple to operate, accurate and reliable in result, easy to master by engineering technicians, and applicable to evaluation of monitoring results of cable forces of prestressed concrete bridge steel strands and steel strand inhaul cables.

The invention discloses a bending test method for an F-shaped socket and spigot joint of a rectangular pipe-jacking tunnel. The bending test method comprises the following steps: two rectangular pipe-jacking components connected by the F-shaped socket and spigot joint are placed on a supporting system, and the supporting system comprises a fixed support, elastic supports, a temporary support and asliding support; a vertical load applying device is arranged right above a steel lantern ring, the upper parts of the two elastic supports are respectively provided with a pressure sensor, and the lower part of the steel lantern ring is provided with two electric measuring displacement meters; all levels of loads are sequentially applied through the vertical load applying device to obtain test data, and the test data are analyzed and processed to obtain the rotating rigidity model of the rectangular jacking pipe F-shaped socket and spigot joint. The method has the advantages that the operability is high, the elastic support is arranged to simulate the limiting effect of the stratum on the rotation of the joint, the bending mechanical behavior of the rectangular jacking pipe joint can be truly reflected, and a rotation rigidity model of the joint is accurately obtained.

The invention discloses a method and a system for calculating the overall elastic modulus of cracked reinforced concrete. The method comprises the following steps of analyzing and simplifying the common stress characteristic of the reinforced concrete at a crack position; then determining the lengths of the steel bars with higher stress on the two sides of the crack; combining and considering thesimplification result of the crack position and the calculation result of the length of the tensioned steel bar; finally, obtaining the overall elasticity modulus of the cracked reinforced concrete. The method is clear in mechanical concept and simple and convenient to calculate, an effective, simple and convenient practical calculation method can be provided for modulus change of the cracked reinforced concrete, reference can be provided for composite linings and other projects needing to apply modulus change application after concrete cracking, and the method can be widely applied to the technical field of capital construction projects.

The invention discloses a design method for a steel and concrete combined continuous beam hogging moment area. Firstly, according to the section size of a combined beam and the fitted hogging moment area bottom plate concrete thickness, the common section inertia moment I and the fulcrum hogging moment area section inertia moment I' of the combined beam are calculated; a continuous beam calculation model in which full-bridge section inertia moments are I is established, and the midspan maximum sagging moment Mmax and the fulcrum maximum hogging moment Mmin under the action of the constant load are calculated; the equation F(lambda)=0 is solved, and lambda is obtained through calculation; and according to L'=lambdaL, the hogging moment area bottom plate concrete section length L' of the combined beam is obtained through calculation, and hogging moment area design is finished. According to the design method, the steel and concrete combined continuous beam hogging moment area length obtained through derivation of the structural mechanics method serves as the hogging moment area bottom plate concrete section length, the hogging moment area design of the steel and concrete combined continuous beam can be rapidly finished, and the design method overcomes the defects that during engineering design, subjective randomness is large, and pilot calculation is repeated; and a series of advantages that the mechanics concept is clear, and universality is high are achieved.

The invention provides a method and a device for optimizing a finite element iteration process based on deep learning, and relates to the technical field of civil structure engineering and computers. The method comprises the following steps: establishing a single unit finite element model based on a constitutive relationship; performing iterative calculation solution on the single unit finite element model, and summarizing iteration process data to form a data set; carrying out deep learning on a difficult-to-converge data set of a single unit finite element model; and establishing a real structure finite element model according to the constitutive relationship and the deep learning model, defining a load working condition and a loading and unloading path according to the actual stress condition of the structure, obtaining a finite element simulation result of the real structure, and completing an optimization finite element iteration process based on deep learning. According to the method, prediction of the next state point in iteration is achieved through the deep learning algorithm, the number of iteration steps is reduced, the calculation efficiency and convergence of the finite element model are optimized on the basis that the accuracy of the simulation result is guaranteed, and high universality is achieved.