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308 results about "Friction angle" patented technology

Angle of internal friction (friction angle) A measure of the ability of a unit of rock or soil to withstand a shear stress. It is the angle (φ), measured between the normal force (N) and resultant force (R), that is attained when failure just occurs in response to a shearing stress (S).

Improved soil matrix and remediation method for green mine

The invention provides an improved soil matrix and a remediation method for a green mine. According to the improved soil matrix and the remediation method for the green mine, a certain gradient of a mountain is formed by trimming a cliff of the mine, a hard material is laid in a certain mode, then a plastic-coated metal net covers the hard material, and finally, the novel improved soil matrix covers the plastic-coated metal net with a certain thickness so as to realize the effective remediation of the mine. The improved soil matrix and the remediation method for the green mine have the beneficial effects that the improved soil matrix can stably float on the surface of the mine with the gradient of less than 80 degrees, the adhesive force is greater than 20 Kpa, the inner friction angle isgreater than 18 degrees, the anti-corrosion index is greater than 99.1%, the anti-scouring index is greater than 2.0 L.min/g, the structure is high, and scouring of heavy rainfall or heavier can be effectively resisted after three days of spraying; the improved soil matrix is rich in nutrition, loose and breathable, and is suitable for growth of plants; and lots of organic matter such as agricultural and forestry leftovers are adopted, so that the water storage performance is high, and the construction cost and the maintenance cost are greatly saved.
Owner:杰瑞(莱州)矿山治理有限公司

Inclined plane instrument device for measuring friction coefficient and friction angle of granular materials

The invention belongs to the field of physical property detection of materials and particularly relates to an inclined plane instrument device for measuring the friction coefficient and the friction angle of granular materials on different material plate elements. Firstly, operators uniformly pave the granular materials to be measured onto a placed plate element, in addition, the included angle between the plate element and the horizontal plane is continuously increased until the materials on the plate element fall into a material collecting disc, and then, the friction angle or the friction coefficient is obtained through a measuring device. The device adopts a rocker mechanism and has a self locking function, and the measuring device comprises a circular arc ruler and a straight rule. Through the self locking function, the operators can release a rocker in experiments for intently regulating the sight line and observing readings. The fixed connection of the upper end and the lower end of the circular arc ruler and the straight ruler adopts a connecting plate with a certain thickness, and the warping in the vertical direction is avoided, so the measurement precision is ensured, and the effect of side plate reinforcing ribs is realized. The design of the material collecting disc at the lower part fully considers the requirements of multiple repeated experiments. The device has the advantages that the external connection of a power supply is not needed, and the device can be placed on the ground or a horizontal test table in a laboratory.
Owner:CHINA AGRI UNIV

Modeling method for compact sandstone reservoir three-dimensional fracability model

ActiveCN105134156AImproving the effectiveness of volumetric fracturingShorter payback timeFluid removalSpecial data processing applicationsModel methodWell placement
The invention relates to a modeling method for a compact sandstone reservoir three-dimensional fracability model. The method comprises the following steps: S1, establishing a relation formula among an internal friction angle, I type and II type crack fracture toughness and the parameter of sandstone mechanical characteristics; S2, establishing a shale fracability evaluation model which comprehensively considers an elastic parameter, the internal friction angle, the critical strain energy release rate and fracture toughness; S3, adopting a support vector machine algorithm to obtain a cluster analysis mode between the reservoir fracability and the elastic parameter; S4, adopting the cluster analysis mode to obtain a reservoir three-dimensional elastic parameter data body, and establishing the multi-scale compact sandstone reservoir three-dimensional fracability evaluation model based on the core, the borehole and the reservoir of multiple scales. According to the method, the fracability of an arbitrary space position in the compact sandstone reservoir can be obtained, a sweet spot with high fracability can always be drilled when drilling a compact sandstone gas well, blindness of well location selection is avoided, and the fracture modification effect and the yield after fracture are improved.
Owner:SOUTHWEST PETROLEUM UNIV

Variable-tooth gear with sliding-sheet deforming teeth

A variable-tooth gear with sliding-sheet deforming teeth pertains to the technical fields of gearing, and continuously variable mechanical transmissions. The variable-tooth gear is designed in accordance with “the principle of configuring variable-teeth through infinitely deforming sliding-sheets”. The working surface is composed of a large number of thin sliding-sheets (sliding-needles) superposed on one another. The meshing tooth profiles of arbitrary shapes can be configured by the free and infinite sliding of the sliding-sheets. Since the direction of sliding of the sliding-sheets is different from the direction of forces acting thereupon, the sliding-sheets can freely deform with the current tooth profiles. The direction of the force acting upon the sliding-sheet when transmitting power is perpendicular to the free-sliding direction, or the angle therebetween is within the equivalent friction angle, therefore the sliding-sheet possesses the self-locking property. The tooth profile thus remains unchanged when the sliding-sheets are under stress. All the sliding-sheets form an integrally closed elastic enclosure ring, possessing the effect of “rigidity and flexibility being combined, variable-tooth being fixed”. Therefore the load capacity is high, the transmission is a one-stage transmission and the transmission efficiency is high. There are only two key components, such that the structure is simple, the cost is low and the size is compact. This variable-tooth gear realizes, to the core, the concept of “continuously variable transmission via gear meshing”, and can be applied to vehicles or industrial fields of high speed and large power.
Owner:BEIJING VIT MOBILE TECH

Method utilizing logging information for determining optimal perforation layer for SRV fracturing

InactiveCN105114047AConvenient and efficient calculationComputationally efficientFluid removalType fractureReservoir volume
The invention discloses a method utilizing logging information for determining the optimal perforation position for SRV (Stimulated Reservoir Volume) fracturing. The method comprises the following steps: (A) calculating mineral friability index B1 by using conventional logging information, elemental capture spectroscopy logging information and natural gamma spectroscopy logging information; (B) calculating dynamic Young modulus E and dynamical poisson ratio v of each layer section by using acoustic logging information and calculating a mechanical friability index B2 of each layer section; (C) calculating total friability index BTot of the layer sections; (D) calculating confining pressure Pc; (E) calculating rock tensile strength St of the layer sections; (F) calculating an I type fracture toughness value KIC and an II type fracture toughness value KIIC of the each layer section; (G) calculating an inner friction angle of each layer section by using logging information; (H) calculating the reservoir compressibility index Frac of each layer section; and (I) selecting a layer section with a high reservoir compressibility index Frac as the optimal SRV fracturing perforation layer. The method is capable of conveniently and efficiently calculating the compressibility index of each layer section by directly using the logging information, so as to provide decision basis for selecting the optimal SRV fracturing perforation layer and promoting exploitation of shale reservoirs.
Owner:SOUTHWEST PETROLEUM UNIV

Testing method for interlaminar shearing stress state

The invention relates to a testing method for the interlaminar shearing stress state, which is a method for evaluating the shearing strength between a cement concrete deck and an asphalt pavement layer. The method can simultaneously acquire the cohesive force C and the friction angle between interfaces by testing once, and is a reasonable testing method for the shearing strength between the cement concrete deck and the asphalt pavement layer. The testing method comprises the following steps: (a) an inclined plane with an inclined angle of 5 degrees-30 degrees, namely a rigid triangular block (8), is arranged in a direction vertical to load application (4); a horizontal force-measuring device (5) is positioned behind the rigid triangular block (8); a loading specimen (1) and a fixed specimen (3) are positioned in a clamp (10); the load vertically applied to the loading specimen (1) is converted into a horizontally applied force to realize application of positive pressure on a shearing interface (2); (b) bearing balls (9) are arranged on the inclined plane to eliminate the effect of the frictional force on the inclined plane to the test result; and (c) based on the testing method, the cohesive force and the friction angle between the interfaces are acquired by calculating with a calculation formula as shown in the specification.
Owner:SOUTHEAST UNIV

Method for measuring maximum scour depth of viscous debris flow gully bed and application thereof

The invention discloses a method for measuring the maximum scour depth of a viscous debris flow gully bed and the application thereof. The method comprises the following steps: weight Gamma1, depth h and a dynamic friction angle Beta of a viscous debris flow body, weight Gamma2, an internal frictional angle Phi and a viscosity coefficient C of cumulus deposits of an original gully bed, and vertical gradient J of the gully channel are determined by means of survey, measurement and sampling of the debris flow gully, testing of debris flow characteristic parameters and the like; and the obtained parameters are substituted into a calculation formula to obtain the maximum scour depth of the viscous debris flow gully bed. The method is applicable to the design of foundation embedded depth in a viscous debris flow prevention project, and the obtained maximum scour depth of the viscous debris flow gully bed serves as the minimum foundation embedded depth in the prevention project. Compared with the prior art, as the method is based on rigorous theory derivation, the maximum scour depth of the viscous debris flow gully bed can be reasonably determined, and references on the design of the foundation embedded depth in the prevention project are provided; and the method is high in result accuracy and can meet the requirements of the practical project.
Owner:INST OF MOUNTAIN HAZARDS & ENVIRONMENT CHINESE ACADEMY OF SCI

Method for calculating surrounding rock pressure of shallow tunnel

The invention relates to the technical field of tunnel engineering. A method for calculating the surrounding rock pressure of a shallow tunnel comprises the following steps: selecting a convergence deformation monitoring point of the surrounding rock; constructing a structural mechanics model at the monitoring point; deriving a calculation relation between the convergence deformation and the surrounding rock pressure; substituting engineering actual data and convergence monitoring data into the calculation relation to calculate the displacement on the left and right sides of the monitoring point and the convergence deformation of the monitoring points; and calculating the surrounding rock friction angle and the surrounding rock pressure. The method analyzes a relationship between the convergence deformation and the surrounding rock pressure of the sidewall surrounding rock in the construction of a double side wall tunneling method, establishes the structural mechanics model, and obtains the surrounding rock pressure from the field monitoring data by means of back calculation. Compared with a calculation method that depends on empirical parameters, the method of the invnetion is more accurate and more represents the actual surrounding rock pressure of the tunnel, and the convergence deformation data of the tunnel is easier to obtain and the calculation is convenient and accurate.
Owner:SOUTHWEST PETROLEUM UNIV

Universal design calculation method for deep/shallow-buried vertical surrounding rock pressure of tunnel and underground space

The invention discloses a universal design calculation method for deep / shallow-buried vertical surrounding rock pressure of a tunnel and an underground space. The method comprises the following steps of: 1, determining shapes and sizes of the tunnels and underground spaces: buried depth (H), unlined tunnel semi-width (alpha), stratum sliding surface semi-width (alpha1), tunnel height (y) and tunnel length (L); 2, determining physical parameters according to geological conditions and surrounding rock levels of the tunnel and the underground space: surrounding rock cohesive force (c), internal friction angle (phi), unit weight (gamma), Poisson ratio (mu) and initial side pressure coefficient (xi); 3, calculating and designing the following contents according to above known physical parameters: 3.1 average vertical ground pressure <delta>flat of the tops of deep / shallow caverns; 3.2 deep / shallow buried boundary depth Hmax, wherein the tunnel is a shallow-buried tunnel when the buried depth is less than Hmax, and the tunnel is a deep-buried tunnel when the buried depth is greater than or equal to Hmax; and 3.3 vertical ground pressure of the shallow-buried cavern. According to the method, no load mutation phenomenon is generated at the deep / shallow-buried boundaries, and through plenty of actual measurements and verifications, the condition is identical to the practical condition.
Owner:中国市政工程西北设计研究院有限公司

Determination method and apparatus for coefficient of earth pressure at rest

The invention provides a determination method and a determination apparatus for the coefficient of earth pressure at rest, belonging to coefficient measuring methods and apparatuses for soil tests. In a conventional triaxial pressure chamber, an axial deformation constrained radial loading test is carried out on a soil sample so as to obtain a ratio of axial stress to radial stress; according to a two-dimensional asymptotic state criterion, relationship between a starting friction angle and a triaxial compression friction angle in the axial deformation constrained radial loading test satisfies equation I described in the specification, and relationship between the starting friction angle and the triaxial compression friction angle in a radial deformation constrained axial loading test satisfies equation II described in the specification. According to calculation results, the coefficient of earth pressure at rest in the axial deformation constraint radial loading test is 0.5 time of the ratio of axial stress to radial stress in the axial deformation constraint radial loading test. According to the method, errors generated when fixed section radial deformation control is used to substitute radial deformation control in a vertical direction of the soil sample in the radial deformation constrained axial loading test for the coefficient of earth pressure at rest can be avoided, and the method and the apparatus are suitable for accurate determination of coefficients of earth pressure at rest of saturated sand.
Owner:CHINA UNIV OF MINING & TECH

Stability analysis method for hydromechanical coupling of unsaturated soil slope

The invention provides a stability analysis method for hydromechanical coupling of an unsaturated soil slope, and belongs to the technical field of rock and soil. According to the stability analysis method, a Barcelona basic model more conforming to the property of the unsaturated soil is adopted for a constitutive model of the unsaturated soil, and the influence of suction force and the influenceof shear strength and compressive strength of a soil body are considered in the constitutive model. According to the strength reduction method for unsaturated soil slope stability analysis, the shearstrength of a soil body is reduced by reducing the cohesive force and the friction angle of the soil body. In addition, the reduction of the compressive strength of the soil body is taken into account by reducing the consolidation pressure in front of the soil body. The stability analysis of the unsaturated soil slope is carried out under the Cosserat continuum frame, and the influence of the microstructure effect of the soil body on the stability of the macroscopic slope is considered to a certain extent. According to the stability analysis method, various influence factors are considered, and the stability analysis accuracy of the unsaturated soil slope is improved.
Owner:CHENGDU UNIVERSITY OF TECHNOLOGY +1

Universal milling force modeling method for uniform plough model

The invention discloses a universal milling force modeling method for a uniform plough model, which solves the technical problem in the prior art that existing universal milling force modeling methods are poor in versatility. According to the technical scheme of the invention, the ploughing force is uniformly expressed as the product of the ploughing force factor multiplied by the volume of the extruded material. Meanwhile, the ploughing force is separated, so that the influence of the ploughing effect on the shearing factor is avoided. Firstly, several sets of static milling experiments are conducted, and the data of the milling force are recorded. Secondly, the milling force measured in a cartesian coordinate system is converted into the milling force in a milling cutter local coordinate system, and the value of the ploughing force in the local coordinate system is determined through the linear regression method. Thirdly, the factor of the milling force is calculated through separating the shearing force from the milling force, and then is compared with an experimentally measured value. Through the repeated iteration process, the data of the shear angle and the data of a normal friction angle are obtained, and then the factor of the shearing force is determined. Therefore, the factor of the ploughing force is determined based on the separated ploughing force and the determined volume of the static extruded material. By adopting the uniform plough model, whether the cutting process is stable or not no longer needs to be judged. Therefore, the method is good in versatility.
Owner:NORTHWESTERN POLYTECHNICAL UNIV

Method for processing roadbed by means of matching of waste tire piece bodies and reinforced soil

The invention discloses a method for processing a roadbed by means of matching of waste tire piece bodies and reinforced soil. The method includes the steps that (1) a waste tire is recycled and cut into pieces, soil used for the actual engineering roadbed is sampled, the recycled waste tire pieces are mixed into the soil, a triaxial compression experiment for solidification water discharging is carried out, an optimum ratio is determined according to the result of shearing strength, and accordingly the soil of the roadbed is improved; (2) geogrid is installed on a flat and compressed field, the stressed direction of the geogrid is vertical to the axis direction of a road embankment, the geogrid is pressed and fixed through plug pins, soil and stones, and the geogrid is under a tightened and stressed state in soil; (3) after the geogrid is laid and positioned, the geogrid is timely covered with soil, and the time when the geogrid is naked cannot exceed 48 hours; (4) in an reinforced soil project, water discharging must be well processed, and when necessary, geotechnical cloth should be arranged. The method can improve the water permeable performance of the roadbed; the shear-resistance is improved due to the fact that soil inner friction angles are increased; soil self-weight is reduced, the problem that the roadbed subsides unevenly is reduced, retaining wall soil pressure is reduced, and the structure of the roadbed is optimized.
Owner:SHANDONG UNIV

Apparatus and test procedure for measuring the cohesive, adhesive, and frictional properties of bulk granular solids

A test apparatus for measuring the cohesive, adhesive and frictional properties of bulk solids has a bulk solid sample confined between two essentially parallel plates with a single load applied that produces both shear and normal stress and strain to the bulk solid in a manner that nearly uniformly distributes stress throughout the granular solid test region. The apparatus has a close proximity of the plates compared with the length of the plates in the direction of shear, the design of a load hanger to produce a resultant load near the shear plane, the roughening of any surface in contact with the solid that is not intended to have shear on it and involves one-directional movement of the parallel plates with respect to each other and the control of both the direction and magnitude of the applied load relative to the parallel plates. A test method uses the apparatus to measure the unconfined yield strength angle of internal friction and steady state deformation effective angle of internal friction with a single test. A test method uses replacement of the lower part of the test sample with a plate of material that the bulk solid may be required to slip on and measures the friction angle and adhesion of the bulk solid on the plate of material.
Owner:JR JOHANSON

Cardio-pulmonary resuscitation device

The invention relates to a cardio-pulmonary resuscitation device. The problems that in an existing cardio-pulmonary resuscitation process, platform switching is low, and operation is complex are solved. According to the technical scheme, the device comprises a first box, a flat plate is arranged in the box which is provided with a rack, a first gear is meshed with the rack, a first threaded rod isarranged on the first gear, a threaded pipe is arranged on the first threaded rod, and a flexible device is installed on the flat plate; a hollow circular pipe is arranged on the flat plate, a secondbox is arranged on the upper portion of the hollow circular pipe, two connecting rods with two lower ends hinged to each other are arranged in the second box, a coiling wheel is arranged between thetwo connecting rods, a rope is arranged on the coiling wheel, a second threaded rod is arranged in the hollow circular pipe, a nut cooperatively sleeves the second threaded rod, the upper end face ofthe nut is rotatably connected with the hollow circular pipe, the lead angle of the second threaded rod is larger than the equivalent friction angle of a screw pair formed by the second threaded rod and the nut, a ratchet wheel sleeves the outer side of the nut, and a pawl matched with the ratchet wheel is installed on the hollow circular pipe. The device is novel in conception, ingenious in structure and high in practicability.
Owner:THE FIRST AFFILIATED HOSPITAL OF HENAN UNIV OF SCI & TECH

Material wear life predicting method, material wear life predicting equipment, and material wear test apparatus

The invention discloses a material wear life predicting method, material wear life predicting equipment, and a material wear test apparatus. The material wear life predicting method comprises: settingtest condition parameters; obtaining the friction performance data of a material in the test condition and the failure critical hardness of the material; processing the data to obtain change relationship of the friction performance of the material; and according to the change relationship and the failure critical hardness, calculating the wear life of the material. The material wear test apparatus comprises: a base disc; a grinding sheet for rubbing against a sample and fixed on the base disc; a temperature control unit for controlling the temperature of a test environment; a pressure controlunit for applying constant pressure onto the sample; a balance arm, wherein one end of the balance arm is coaxially connected to the sample, and the friction angle of the sample on the grinding sheetis changed by adjusting the balance arm; and a drive unit connected to the base disc and used for controlling the rotation speed and the rotation direction of the base disc. With the method, the equipment and the apparatus, the wear life of the material can be accurately predicted, and test efficiency and the test economy can be improved.
Owner:HITACHI LTD

Manufacturing and test method of rock compression shearing test specimen containing intermittent joints at high temperature

The method for making and testing rock compressive shear samples with discontinuous joints at high temperature in the present invention includes: 1) making rock compressive shear samples with discontinuous joints; 2) using rock compressive shearing samples with discontinuous joints The sample is tested for shear strength: a) Use the rock high-temperature triaxial compression test equipment to directly load the sample, carry out the rock compression test with discontinuous joints, and measure the shear strength with discontinuous joints; b) Use the rock high temperature The triaxial compression test equipment conducts the joint shear test under high temperature and high pressure conditions in the temperature and pressure chamber and the acoustic emission AE and CT scanning research during the test process: C) The shear plane of the rock compression shear sample with continuous joints is 10℃~ Testing of shear strength indicators (cohesion and internal friction angle) at 200°C. The invention can carry out acoustic emission (AE) test during sample compression and CT scanning test in compression process, has the advantages of exploring the effect of temperature and pressure conditions on joint properties, and makes up for the deficiencies of traditional rock samples.
Owner:CHENGDU UNIVERSITY OF TECHNOLOGY

Rapid clamping fixture with adjustable pressing force

The invention relates to a rapid clamping fixture with adjustable pressing force. The middle of a connecting rod is connected with a pressing plate in a penetrating manner, and the lower end of the connecting rod is fixedly connected with a working table through a T-shaped nut; a long kidney-shaped hole is formed in a straight slot in the upper portion of the connecting rod, and an eccentric semicircular block is movably connected with the long kidney-shaped hole through a hinge pin; an adjusting bolt and a locking nut are arranged at the upper end of the connecting rod, and a bevel washer arranged on the connecting rod in a sleeving manner is arranged on the pressing plate; and the part, between the pressing plate and the working table, of the connecting rod is sleeved with a reset spring, and a rotating handle is arranged on the eccentric semicircular block. According to the clamping fixture, through the eccentric semicircular block, a workpiece is rapidly clamped, the bevel washer is utilized for conveniently adjusting the clamping force, a friction angle on the contact position of the bevel washer and the eccentric semicircular block is used for locking, and the pressing force of the eccentric semicircular block can be fine adjusted through the adjusting bolt and the locking nut after the workpiece with elastic deformation is pressed; and due to the fact that the part, between the pressing plate and the working table board, of the connecting rod is sleeved with the reset spring, after the eccentric semicircular block is loosened, the pressing plate automatically loosens the workpiece under the effect of the reset spring.
Owner:陈敏蓉
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