1036 results about "Shear force" patented technology

The invention discloses a double-row anti-slide pile internal force obtaining method and system, and relates to the field of geotechnical engineering.The double-row anti-slide pile internal force obtaining method comprises the steps that indoor experiments are conducted on pile top displacement, pile periphery soil pressure distribution and pile body bending moment and shearing force distribution of a coupling-beam-free double-row anti-slide pile, and the stress characteristics and deformation characteristics of the coupling-beam-free double-row anti-slide pile are obtained; constructing a coupling-beam-free double-row anti-slide pile internal force calculation model; an anti-slide pile is simplified into an elastic foundation beam with a fixed range above a slide surface as a directional support, a pile structure is divided into a load-bearing section and a load-bearing section-built-in section from the directional support, and the internal force of the coupling-beam-free double-row anti-slide pile is determined; the stress and deformation characteristics of the coupling-beam-free double-row anti-slide pile are input into the coupling-beam-free double-row anti-slide pile internal force calculation model, and the internal force of the whole pile body of the coupling-beam-free double-row anti-slide pile is accurately obtained.

The invention discloses an I-shaped column-full dry type connection RC beam column joint and a connection method, and belongs to the technical field of building structure engineering. The joint comprises a prefabricated I-shaped column, a stepped beam, a shear connector and a U-shaped connecting steel plate. A long bracket and a short bracket are respectively arranged at the top and the bottom of the I-shaped column; the end part of the step-shaped beam is in an inverted step shape and is provided with an extending section; the shear connector is a long-strip-shaped steel member provided with a screw rod; and the U-shaped steel plate is provided with screw holes which are respectively matched with the shear connector and the beam end screw. During connection, rapid assembly is achieved in the mode that the brackets of the upper column and the lower column are in lap joint, shear key grooves are interlocked, the shear connectors penetrate into the square holes, the beam bodies are supported on the combined brackets, and finally the U-shaped steel plates are used for anchoring. According to the joint, complete dry type operation is achieved, cast-in-place concrete and steel bar welding are not needed, the construction efficiency is remarkably improved, wet operation is reduced, loads can be borne after installation, the overall performance is reliable, and the development requirement of fabricated buildings is met.

A damping partition wall design method having variable friction energy dissipation, comprising the following steps: establishing an empty frame model which does not consider the lateral stiffness resistance of a partition wall, and calculating the inter-story shear force and inter-story displacement of a structure under the action of an earthquake; calculating the elastic strain energy of the structure, and determining an expected additional damping ratio provided by the damping partition wall for the structure; determining a friction damping force-sliding displacement curve of a single group of damping partition walls, and establishing a relational expression of total friction hysteresis energy dissipation and the friction damping force and target sliding displacement of the single group of damping partition walls; comparing a calculated additional damping ratio and the expected additional damping ratio to obtain the relationship thereof, and determining the friction damping force requirement of the single group of damping partition walls; designing elastic pieces; designing anti-shearing connecting pieces; and carrying out damage control verification. According to the damping partition wall having variable friction energy dissipation, parametric design and adjustment are carried out on the basis of the design goal of the structure, so that there are regulations to follow in the design of such a damping partition wall, and the anti-seismic toughness of the partition wall and structure can be synergistically improved.

The invention relates to the technical field of bridge construction, and discloses a guide-beam-free incremental launching construction hoisting balance weight structure for bridge construction, which comprises an incremental launching platform and a gantry crane above the incremental launching platform, the counterweight assembly comprises two slide rails, two wheel carriers, two groups of rollers, a base, a plurality of counterweight blocks, two groups of guide wheels and two pull ropes; and the lubricating assembly is used for lubricating the two groups of rollers. Through the arrangement of the counterweight assembly, the base can move reversely along with the movement of the gantry crane, self-adaptive position adjustment of the multiple counterweight blocks is achieved, the gantry crane and the multiple counterweight blocks are kept in a balanced state on the pushing platform, the bending moment and the shearing force peak value of the pushing platform are reduced, and through the self-adaptive position adjustment, the service life of the pushing platform is prolonged. And the operation of actively adjusting the position of the balancing weight by an operator is reduced, and the operation time is saved.

The invention discloses a concrete-filled steel tube column and split-level reinforced concrete frame beam joint and a construction method, the concrete-filled steel tube column and split-level reinforced concrete frame beam joint comprises a concrete-filled steel tube column body, a cross-shaped fixing frame is fixedly mounted in the middle of the concrete-filled steel tube column body, and a first split-level reinforced concrete beam is mounted at the top end of one side of the cross-shaped fixing frame; a first split-level reinforced concrete beam is installed at the bottom end of one side of the cross-shaped fixing frame, a second split-level reinforced concrete beam is installed at the bottom end of the other side of the cross-shaped fixing frame, and first profile steel brackets are installed on the two sides of the connecting position of the first split-level reinforced concrete beam and the cross-shaped fixing frame. A built-in anti-bending steel corbel transition section is adopted to arrange an anti-shearing stud in a built-in steel cow leg section to ensure the cooperative work of a beam end combination section, and the combination section resists the bending moment transmitted by the beam end; meanwhile, an anti-shearing steel corbel is combined to resist shearing force; on the basis of the current specifications and atlas, the structure of the concrete filled steel tube and split-level beam connecting joint is supplemented.

The invention belongs to the technical field of segment splicing type bridges, and particularly relates to an anti-shearing structure of a segment splicing box girder and a construction method of the anti-shearing structure. The shear-resistant structure comprises a box girder body composed of a top plate, a web plate and a bottom plate, and further comprises two formwork units arranged at the two ends of the box girder body respectively in a pouring fixing mode, and a shell arranged on the formwork units and used for forming a concave key structure or a convex key structure of a shear key. The shear-resistant structure has the beneficial effects that the shear key formwork part of the shear-resistant structure at least comprises the formwork units and the shell, the shear key formwork part can effectively form the box girder body, does not need to be taken down during formwork removal and can also be used as a concave key structure and a convex key structure, and therefore the shear-resistant structure is simple and efficient during manufacturing and construction; and the precision is relatively high during splicing construction.

To provide a method for removing a floor slab of a composite girder capable of reducing concrete remaining on the girder.SOLUTION: Since a cutting-in 5 extending in the bridge-axis direction is formed from the upper surface side of a floor slab at each arrangement location of a slippage preventing member 4 of a floor slab 3, and the floor slab 3 on which the cutting-in 5 is formed is pulled upward from main girders 2 and removed, the resistance force between the slippage preventing member 4 and the concrete of the floor slab 3 against the tensile load can be reduced by the cutting-in 5, and the floor slab 3 can be easily separated from the main girders 2. Thus, since it is not necessary to cut the floor slab 3 in the bridge axial direction such that concrete remains on the main girder 2 as in the related art, the floor slab 3 on the main girder 2 can be lifted and removed at once without being divided in the direction perpendicular to the bridge axis. As a result, the efficiency of the removal work can be improved, and there is an advantage that a large-scale concrete crushing work is not required.SELECTED DRAWING: Figure 5

The invention relates to the technical field of flame-retardant cables, and particularly discloses a drip-proof flame-retardant cable and a preparation method thereof.The drip-proof flame-retardant cable comprises conductors and further comprises an elastic supporting layer, and the outer surfaces of the five conductors are wrapped with the elastic supporting layer. According to the drip-proof flame-retardant cable and the preparation method thereof, when the cable is bent, the elastic supporting layer can perform elastic pressure relief on the shearing force of wind, so that the bending strength of the cable is reduced, and the situation that the cable is greatly shaken due to the fact that the cable is often influenced by strong wind in coastal areas is avoided; when the cable is partially bent, the filling cavity at the bent part is extruded, so that the oxygen barrier layer is prevented from generating microcracks at the bent part, and the risk that rainwater permeates into the cable and is vaporized and exploded at high temperature when encountering an electric arc is avoided. Therefore, the non-Newtonian fluid in the local filling cavity is locally hardened under the action of the extrusion force, the bending strength of the cable is greatly reduced, and the internal conductor is protected.

The invention relates to the technical field of pressure monitoring, and discloses a method and system for motion state analysis according to plantar pressure, and the method comprises the steps: receiving multi-modal biomechanical data related to a landing event; extracting a corresponding motion feature vector from the multi-modal biomechanical data; and inputting the motion feature vector into a motion state analysis model for identification to obtain a corresponding damage risk index, and outputting the corresponding damage risk index. By receiving pressure distribution data detected by the plantar pressure sensing array, shear force data detected by the shear force measuring and calculating module and a kinematics data sequence detected by the inertial measurement unit, biomechanical information in the movement process can be comprehensively captured from multiple dimensions; compared with a single data acquisition mode, the fusion of the multi-modal data can reflect the real state of the human body in motion more accurately, and a richer and more accurate data basis is provided for subsequent motion state analysis.

The invention relates to a multifunctional test loading device for simulating bending shear torsion performance of a wind power tower, which comprises a counter-force column, a counter-force longitudinal beam, a counter-force cross beam and four actuators, and is characterized in that the counter-force cross beam is fixed at the top of the counter-force longitudinal beam through a bolt and is connected with a first actuator for axially applying pressure; the bottom of the tower drum is connected and fixed through a loading support with a kidney-shaped hole, and the end of the tower drum is connected with a loading beam through a conversion piece and abuts against a first actuator for axial pressure applying and loading. A fourth actuator on one side of the reaction wall is used for applying horizontal shearing force and torque; second and third actuators on the upper and lower sides of the counter-force longitudinal beam are used for applying bending moment; according to the device, loading of multiple load types can be achieved on the tower drum, the complex stress condition possibly borne by the tower drum in the actual use process can be simulated, and loading of any change of a single load of the tower drum can also be simulated; the device is suitable for loading and fixing tower barrels of different types and sizes; and the influence of torsional deformation and horizontal displacement on vertical load loading can be reduced through structural measures.

The embodiment of the utility model provides a roadbed slope reinforcing device which comprises a supporting frame used for providing support and provided with a plurality of mounting connectors, reinforcing ribs are arranged in the supporting frame to improve the lateral pressure resistance, inclined wing faces are arranged on the two sides of the supporting frame, and embedded locking pieces are further arranged to ensure stable structural connection; the anchor rod is connected with the supporting frame, goes deep into soil and is used for anchoring the whole device in a roadbed slope; the reinforcing panel covers the outer part of the supporting frame and aims to form a continuous plane; the shear keys are installed between the supporting frame and the reinforcing panel, and shear force is transmitted through a meshing structure; wherein the embedded locking piece comprises a telescopic locking pin which is used for adjusting the locking force; a spiral blade is arranged on the anchor rod; and an expansion screw is arranged at the tail end of the anchor rod. Through the scheme of the embodiment of the invention, the soil lateral pressure resistance of the device can be improved.

The invention relates to a shear key arrangement device and method for improving the crack resistance of a bridge deck in a hogging moment area of a steel-concrete combined continuous beam bridge, and belongs to the technical field of bridge engineering. Comprising a steel beam, a concrete bridge deck slab and stud shear keys arranged between the steel beam and the concrete bridge deck slab, and the rigidity of the shear keys can be adjusted according to needs so as to improve the stress performance of a concrete slab in a hogging moment area. According to the shear connectivity requirement, the total shear bearing capacity of the studs is calculated, the number of the studs is calculated according to the diameter of the selected stud type, the tensile stress of the concrete in the hogging moment area is calculated and compared with the designed allowable stress, and rigidity adjustment of the shear keys is achieved by changing the diameter and the number of the studs. And meanwhile, the total strength of the stud is kept unchanged. According to the scheme, the stress performance of the concrete slab in the hogging moment area of the steel-concrete combined continuous beam bridge can be effectively improved, meanwhile, the construction process is simplified, the safety is improved, the cost is reduced, the material performance is fully utilized, and the user experience is improved.

The invention provides a liquid film flow simulation method of a power law fluid, which is characterized in that nondimensionalization and simplification are carried out based on a control equation and a constitutive equation of liquid film flow of the power law fluid, and normal stress and shear stress balance conditions on the surface of the liquid film under the action of gravity and airflow shear force are deduced; and according to a liquid film surface boundary condition and a wall surface non-slip boundary condition, an expression of speed distribution in a power law fluid liquid film under the action of airflow shearing is provided. Deriving according to an integral boundary layer method to obtain a differential equation set of evolution of liquid film thickness and flow along with time and flow direction, wherein the differential equation set can be used for researching influence factors of liquid film flow characteristics of the power law fluid; time discretization is carried out by adopting a Runge-Kutta method, spatial discretization is carried out by adopting a finite difference scheme, so that the change rule of the liquid film thickness along with the time and the flowing direction is obtained, and the influence rule of the airflow shear force and the power exponent on the change of the liquid film thickness is discussed.

The invention relates to a wind power tower bending shear torsion test loading anti-interference decoupling switching integrated device, which comprises a reaction wall, a support, a reaction column, a reaction longitudinal beam, a reaction cross beam and four actuators, and is characterized in that the top end of a fixed tower on the support is connected with a loading beam through a switching device; the first actuator applies axial load to the tower drum through the loading beam and the switching device, the second actuator and the third actuator apply bending moment to the end of the tower drum through the loading beam and the switching device, the fourth actuator is matched with the connecting piece, the rectangular steel plate is connected with the switching device to apply horizontal shearing force and torque to the end of the tower drum, and application and decoupling of various types of loads are achieved. The test precision is ensured; the device can truly simulate the load condition of the tower drum section, can also be matched with the loading beam to transmit the axial force, the bending moment, the shearing force and the torque to the wind power tower drum, and effectively solves the influence of horizontal displacement and torsional deformation on loading in the horizontal and vertical load coupling loading process in the wind power tower drum composite load simulation test.

The invention discloses a prefabricated heat preservation groove type plate floor slab system of an assembly type steel structure trestle, and relates to the technical field of groove type prefabricated heat preservation floor slabs, the prefabricated heat preservation groove type plate floor slab system comprises an anti-skid face plate and a heat preservation bearing mechanism, the heat preservation bearing mechanism is arranged at the bottom of the anti-skid face plate, the heat preservation bearing mechanism comprises a plurality of sealing plates, and the sealing plates are arranged in the anti-skid face plate. The multiple sealing plates are arranged and located at the bottom of the anti-skid panel, multiple second supporting blocks are arranged at the bottoms of the sealing plates, groove-shaped plates are arranged on the outer sides of the multiple second supporting blocks, structural blocks are integrally formed through pouring and extruding, reinforcing strips are arranged on the inner walls of the structural blocks, and the structural blocks and annular hoops form a two-way constraint combined framework which can bear bending moment and shearing force; therefore, the bending resistance, the shearing resistance, the torsional rigidity and the overall bearing capacity of the plate body are improved on the premise that heat preservation is not affected on the whole, the engineering problems are avoided, and normal construction work and construction time are maintained.

The invention discloses an accurate prediction method for vertical deformation of adjacent tunnels caused by foundation pit excavation under the action of lateral soil mass, which comprises the following steps: firstly, determining size parameters of a foundation pit and an existing tunnel and physical and mechanical parameters of the tunnel and the soil mass, determining a stress mode of the tunnel and a model sketch of interaction between the foundation pit and the tunnel, and determining additional stress of the tunnel; then establishing a total energy formula of a tunnel upheaval deformation system of a Pasternak foundation model considering the influence of a lateral soil body and axial internal force of the tunnel, and obtaining a tunnel upheaval deformation w matrix analysis based on an energy variation principle; and finally, according to an Euler-Bernoulli beam theory, a bending moment expression and a shearing force expression of the tunnel are obtained. According to the method, the influence of the lateral soil body and the axial internal force of the tunnel on tunnel deformation is considered on the basis of the Pasternak foundation model, so that the data obtained through calculation more conforms to the measured value, matrix analysis is simple and practical, and the method has guiding significance on prediction of vertical deformation of the adjacent tunnel caused by foundation pit excavation.

The present invention discloses a processing method for an emergency breakaway pin for an aircraft main landing gear. The pin is hollow and cylindrical, with two breakaway slots provided in the inner bore corresponding to two locations bearing shear force. A thickened section is provided between the two breakaway slots, and the inner bore diameter corresponding to the thickened section is smaller than that at other locations. The bottom of the breakaway slot is connected to the straight stepped surfaces on both sides by a rounded transition. The emergency breakaway pin of this solution has a breakaway slot design that not only controls precise breakaway but also limits the breakaway area. The rounded transition between the bottom of the breakaway slot and the straight stepped surfaces on both sides improves fatigue strength, and the thickened section between the two breakaway slots improves static strength. The measured breakaway value can be controlled within a range of ±4% of the set threshold, achieving precise breakaway.

A retention system is for a wear part for a bucket for an earth moving machine. The retention system has in operational use: i) a bucket body having a trench; ii) a force multiplier having a shape substantially corresponding to a shape of the trench; iii) a wear part mounted to an edge of the bucket body, and iv) a plurality of bolts. The wear part and the force multiplier is provided with at least one protrusion and another one of the wear part and the force multiplier is provided with at least one matching recess such that relative movement between the wear part and the force multiplier in a lateral direction parallel to the first mutual interface is prevented, in operational use, for reducing shear forces acting on the bolts.

The invention relates to a ring groove rivet sleeve and a high-strength ring groove rivet for aerospace, the rivet sleeve comprises a bulged section, a connecting section and a locking section which are sequentially distributed in the axial direction, and the material strength of the bulged section and the locking section is smaller than that of the connecting section. According to the rivet sleeve, the bulged section, the connecting section and the locking section are sequentially distributed in the axial direction, the bulged section penetrates through the hole of the connected piece during riveting, the connecting section is located in the hole in the connected piece, the locking section abuts against the side face of the connected piece, the bulged section is bulged and deformed in the riveting process, and the locking section is located in the hole in the connected piece. Meanwhile, the locking section is extruded to deform and is filled into a thread groove in the rod part of the nail rod to realize locking; due to the fact that after riveting is completed, the rivet mainly bears shearing force through the connecting section, the material strength of the connecting section is set to be larger than that of the bulging section and the locking section, smooth deformation of the bulging section and the locking section can be guaranteed, meanwhile, the structural strength of the connecting section is improved, the connecting section has high shearing strength, and the service life of the rivet is prolonged. And the shear resistance of the rivet can be effectively improved.

The invention discloses a contact resistance-based method for synchronously measuring normal force and shear force of an interface, which comprises the following steps of: inspired by a yield criterion of material damage, establishing a relationship between normal stress and shear stress of the contact interface, thereby obtaining a relationship between a real contact area of the contact interface and the normal force and the shear force; obtaining the relationship between the contact resistance of the contact interface and the real contact area, and establishing the relationship between the contact resistance of the interface and the normal force and the shear force; according to the geometric deformation relation of the micro-convex bodies on the contact interface before and after the shearing force acts, the relation between the real contact area of the contact interface and the geometric deformation parameters of the micro-convex bodies is obtained, and the relation among the normal force of the contact interface, the shearing force and the geometric deformation parameters of the micro-convex bodies is obtained; and establishing a simultaneous equation set, measuring the contact resistance, and substituting the contact resistance into the equation set to calculate the normal force and the shear force. According to the invention, the normal force and shear force of the interface can be indirectly measured by measuring the contact resistance of the contact interface.

The invention discloses a corrugated steel web box girder hogging moment area shear nail push-out test device and method.The corrugated steel web box girder hogging moment area shear nail push-out test device comprises a corrugated steel web combined box girder, a loading frame, a pulley support, a jack and a displacement measuring device, and a reinforced concrete plate of the corrugated steel web combined box girder is connected with a corrugated steel web through shear nails; the cross beam of the loading frame applies symmetrical vertical pressure to the reinforced concrete slab through the jack, the stand column applies horizontal push-out force to the lower sliding support through the jack, the reinforced concrete slab is pushed out of the top face of the steel box girder, and a shearing force sliding curve is recorded through the displacement measuring device and the pressure sensor. Through a two-way loading mode of first vertical and then horizontal, the shear bearing capacity of the shear nail under the actual cracking condition of a hogging moment region concrete slab is more effectively simulated, a test device for only applying one-way force to the shear nail is improved, the real stress condition of the continuous beam bridge hogging moment region is met, and the displacement measurement device is simple in structure, stable in clamping and high in practicability. The relative slippage of the shear nails is effectively measured.

The invention discloses a frame structure design method based on rigidity reduction. The method comprises the following steps that 1, rod end bending moments Mb and Mc and axial force Nc of frame beams and columns are obtained through calculation; step 2, obtaining actual reinforcement areas Asb0 and Asc0, section sizes and concrete strength of frame beams and columns; 3, the equivalent stiffness Kb1 of the frame beam is obtained through calculation according to the formula Kb1 = Mb0.75y / phi b0.75y; 4, the equivalent stiffness Kc1 of the frame column is obtained through calculation according to the formula Kc1 = Mc0.75y / phi c0.75y; 5, comparing the equivalent stiffness of the frame beam and the frame column with the initial flexural stiffness, and ending after the deviation is less than or equal to 15%; 6, calculating a shear force design value of the frame beam, calculating stirrups needing to be configured for the frame beam, and rechecking a shear-resistant section; and 7, calculating a shear force design value of the frame column, calculating stirrups needing to be configured for the frame column, and rechecking a shear-resistant section. Compared with the prior art, an overall calculation model of the frame structure is established, the real rigidity of a structural member is obtained through multiple iterations, section reinforcement is optimized, and the reinforcement amount is reduced; and the overall anti-seismic performance is improved.

The utility model discloses an adhesive shear testing device capable of adjusting shear load coaxiality, which relates to the technical field of shear testing and comprises an upper base material, a lower base material, an upper U-shaped connecting piece and a lower U-shaped connecting piece, positioning holes are formed in the two sides of the upper U-shaped connecting piece and the two sides of the lower U-shaped connecting piece correspondingly, positioning adjusting knobs are connected to the inner walls of the positioning holes through threads, pin holes are formed in the middles of the surfaces of the positioning adjusting knobs, and bearing pins are inserted into the inner walls of the pin holes; the upper bearing pin and the lower bearing pin penetrate through the upper base material and the lower base material respectively and extend to the other sides of the upper U-shaped connecting piece and the lower U-shaped connecting piece. According to the utility model, the shearing force is limited in the same plane of the adhesive surface, the torque of the Y axis is avoided, and the test accuracy is improved.

The invention relates to the technical field of roller body welding equipment, and discloses roller body welding equipment and a technology, the roller body welding equipment comprises a welding table, a bearing and transferring assembly is arranged on the welding table, the bearing and transferring assembly comprises supporting plates symmetrically and fixedly arranged at the two ends of the welding table, and a plurality of first air cylinders are fixedly arranged at the lower ends of the supporting plates; the surface of a piston rod of the first air cylinder is sleeved with the same bottom plate, a two-way lead screw is rotationally arranged in the bottom plate, sliding blocks are symmetrically connected to the surface of the two-way lead screw in a threaded mode, a first bearing plate and a second bearing plate are arranged between the two symmetrical sliding blocks, and a sliding groove matched with the second bearing plate is formed in one side of the first bearing plate. By means of the cooperation of the first bearing plate and the second bearing plate which can be connected in a sliding and sleeving mode, a roller body can be stably borne and accurately transferred to the designated position of the welding table, and the roller body slowly rolls to the bearing platform along the inclined face by means of the self weight during discharging; and the non-uniform additional bending moment and shearing force caused by the dead weight of the roller body in the traditional three-point hoisting to a welding seam area are effectively avoided.

The invention discloses a stress and displacement calculation method for multiple rows of anti-slide piles of a reinforced foundation covering type landslide. The method is simple and reasonable in concept and easy to operate. The method comprises the steps that 10, all rows of anti-slide piles are sequentially numbered from 1 to N from the front edge of a slope body; 20, the landslide thrust on the rear side of the loaded section of the N-th row of anti-slide piles is calculated; 30, representing the linear distribution resistance of the front sliding body to the load-bearing section and the horizontal displacement of the load-bearing section; 40, the bending moment M0 and the shearing force Q0 of the bottom end of the loaded section are obtained; 50, obtaining the horizontal displacement x0 and the rotation angle theta0 of the bottom end of the load-bearing section; step 60, simultaneous solution is carried out to obtain x0 and theta0; step 70, obtaining the horizontal displacement and the internal force of the loaded section; 80, the horizontal displacement and the internal force of the built-in section of the slide-resistant pile are obtained; 90, obtaining landslide thrust acting on the load-bearing section of the (N-1) th row of slide-resistant piles by a slide mass between the Nth row of slide-resistant piles and the (N-1) th row of slide-resistant piles through equivalent conversion; and repeating the steps 20-80, and so on, so as to obtain the internal force and displacement of each row of anti-slide piles.

The invention discloses a hybrid control method and device for a shear strength test of a rock mass structural plane, and relates to the technical field of physical property analys.The hybrid control method comprises the steps that the stress accumulation state before shear failure is simulated by controlling shear force to be increased or kept according to a preset function relation; judging whether a first condition for converting from the first mode to the second mode is met or not in real time, switching to the second mode when the first condition is met, controlling the position of the sample to remain unchanged, and simulating a stress release state during shear failure; judging whether a second condition for converting from the second mode to the third mode is met or not in real time; when a second condition is met, switching to a third mode, controlling the sample to slide at a constant rate, and simulating a stress retention state after shear failure; and when the accumulated slippage distance of the sample reaches a preset limit value, ending the test. According to the method, full-stage mechanical behaviors from the moment before damage to the moment after damage are reproduced, and accurate data support is provided for slope stability analysis and anti-sliding design.

The utility model relates to the technical field of composite shear walls, and particularly discloses an assembly type PEC recycled concrete beam column and steel plate composite shear wall which comprises a prefabricated column, a connecting plate is fixed to one side of the outer wall of the prefabricated column, a bearing plate is installed on one side of the connecting plate, and a prefabricated beam is fixed to the side, away from the connecting plate, of the bearing plate. A mounting hole is formed between the connecting plate and the bearing plate, and an assembling mechanism is arranged between the two precast beams; the splicing mechanism comprises a clamping groove, the clamping groove is formed in one side of the outer wall of the prefabricated beam, a sliding groove is formed in one side of the clamping groove, and the prefabricated shear plate can be located between the prefabricated beams through the prefabricated column, the connecting plate, the prefabricated beam, the bearing plate, the clamping groove, the sliding groove, the prefabricated shear plate and a sliding block in cooperation with a positioning groove, a positioning block and a material injection opening. And the situation that the labor intensity is increased while the assembling efficiency is low due to the fact that a plurality of bolts are used for fixed installation is avoided.

The utility model relates to the technical field of feeding mechanisms, and discloses a feeding mechanism for a double-screw extruder, which comprises a feeding barrel, and a double-screw extruder main body is arranged on the lower side of the feeding barrel; the top of the feeding barrel communicates with a feeding pipe, and a stirring assembly is arranged at the top of the feeding barrel. The stirring assembly comprises a motor, a second rotating shaft and a discharging mechanism, a third conical tooth is fixed to the output shaft end of the motor, the output shaft of the motor drives the third conical tooth to rotate, the third conical tooth is in meshed connection with a first conical tooth and a second conical tooth, and the first conical tooth and the second conical tooth drive the first rotating shaft and the second rotating shaft to rotate; the first stirring blade and the second stirring blade rotate in opposite directions, so that raw materials can be more effectively scattered and uniformly mixed, shear force and dispersion force are continuously applied to the raw materials, adhesion and accumulation of the raw materials are effectively prevented, the flowability and machinability of the raw materials are kept, and the downtime caused by non-uniformity or blockage of the raw materials is shortened.

The utility model provides a novel rail vehicle overload and unbalanced load detection device with multiple detection areas, and relates to the technical field of vehicle overload and unbalanced load detection. Comprising a plurality of measuring areas arranged along a steel rail and a terminal, and sleepers are arranged at the bottom of the steel rail at intervals in the extending direction of the steel rail; connecting main beams are pre-buried in ballast beds on two sides of a steel rail in each secondary measurement area respectively, and the connecting main beams on two sides are fixedly connected with two ends of a first number of sleepers respectively; a first shearing force sensor and a second shearing force sensor are arranged at the position, corresponding to the upper portion of each connecting main beam, of the steel rail at intervals so as to detect shearing force data; the terminal is electrically connected with the first shearing force sensor and the second shearing force sensor so as to receive shearing force data, and whether the vehicle is overloaded or not is judged according to the shearing force data. The stability of the structure in the corresponding measuring area is improved, installation is convenient, and compared with the prior art, cost is lower.

The invention discloses a method for accurately predicting upheaval deformation of adjacent tunnels caused by foundation pit excavation by considering the influence of soil friction, which comprises the following steps of: firstly, determining size parameters of a foundation pit and an existing tunnel and physical and mechanical parameters of the tunnel and a soil body, and determining a stress mode of the tunnel and a model sketch of interaction of the foundation pit and the tunnel; determining the additional stress of the tunnel; then establishing a total energy formula of a tunnel upheaval deformation system of a Pasternak foundation model considering soil friction, and obtaining a tunnel upheaval deformation w matrix analysis based on an energy variation principle; and finally, according to an Euler-Bernoulli beam theory, a bending moment expression and a shearing force expression of the tunnel are obtained. According to the method, based on the Pasternak foundation model, the influence of axial soil body friction of the tunnel on tunnel deformation is considered, so that the calculated data better conform to the measured value. The method is simple and practical in matrix analysis, and has guiding significance for predicting the upheaval deformation of the adjacent tunnel caused by excavation of the foundation pit.