134 results about "Direct shear test" patented technology

The invention provides a rock mass real structural surface direct shear value test simulation method, and belongs to the technical field of rock mechanics. Preparing an artificial fracture on the standard rock sample through Brazilian splitting; scanning the surface of the artificial fracture by adopting a three-dimensional scanning technology to obtain point cloud data of a real structural surface of the rock mass; establishing a direct shear test geometric numerical model of the real rock mass structural surface based on the point cloud data; according to the geometric numerical model of the direct shear test of the real rock mass structural plane, establishing a control equation set considering the wear of the real rock mass structural plane; according to the control equation set, numerical simulation of the direct shear test of the real rock mass structural plane considering abrasion is achieved. The method disclosed by the invention lays a solid foundation for accurately knowing and scientifically mastering the shearing mechanical response and wear evolution law of the real structural surface of the rock mass, and improves the accuracy.

The invention belongs to the technical field of frozen soil engineering, and particularly relates to a concrete-frozen soil contact surface direct shear test sample manufacturing device and method.The concrete-frozen soil contact surface direct shear test sample manufacturing device comprises a box body, a counter-force frame, a heating plate and a refrigerating plate, a walking device is arranged at the top of the counter-force frame, a pressurizing device is arranged at the bottom of the walking device, and a pressure gauge is arranged on the pressurizing device; a concrete pouring chamber and a soil sample chamber are arranged below the reaction frame, and a partition plate is arranged between the concrete pouring chamber and the soil sample chamber. The method has the advantage that the problem that the water content of the concrete-frozen soil interface is too high due to water migration caused by the gravity effect is solved.

The invention discloses a multifunctional geotechnical mechanical testing system for controlling temperature, humidity and salinity in an extreme environment, and relates to the technical field of ocean geotechnical engineering and geotechnical engineering. The system integrates a high-precision temperature and humidity and salinity control system, can accurately simulate the influence of complex environments such as extreme temperature and humidity, salt spray corrosion and the like on the mechanical properties of geotechnical materials, supports a direct shear test, a pull-out test, a soil body single-particle crushing test and a geosynthetic material stretching and puncturing test, can distinguish static, dynamic and long-term creep test modes, and can be used for testing the mechanical properties of the geotechnical materials. Comprising creep mechanical property testing under cyclic direct shear and continuous load. A visual monitoring assembly is additionally arranged, so that the microscopic deformation and damage process of the sample can be recorded in real time. Through multifunctional integration, temperature, humidity and salinity joint control, visual monitoring and dynamic and static coupling test devices, the technical bottlenecks of single function, environment simulation limitation and microcosmic observation deficiency of traditional equipment are solved, and high engineering application value and popularization potential are achieved.

The invention relates to a rock multi-surface direct shear test system and method considering fluid-solid coupling, and relates to the field of rock mechanics and seepage mechanics. Comprising a true triaxial loading frame which is used as a supporting frame of a test system and is used for clamping a sample and realizing a true triaxial stress state; the shear loading device is arranged in the true triaxial loading frame and is used for independently applying a horizontal shear load; the seepage module is connected with the true triaxial loading frame and is used for feeding fluid into the surface of the sample; the data acquisition system is used for monitoring and recording stress, strain, displacement, acoustic emission signals and seepage parameters in the test process in real time; and the servo control system is used for coordinating and controlling static loading, shear loading and seepage processes. According to the invention, the loading precision is improved, more real test conditions are provided for safety assessment of deep rock mass engineering and geological disaster prevention and control, and the device has important engineering application value.

The invention discloses a multilevel rock mass mechanical analysis method and system based on near field dynamics, and the method comprises the steps: generating a mica-matrix binary model matched with actual granite based on a K-L random field, mapping the model to a BB-PD model mass point through a DIP method, determining the distribution, the particle size and the content of mica, and determining the particle size of the mica; the mechanical weakening effect is simulated by reducing the normal and tangential stiffness of the mica phase, and the microstructure characterization of the rock is completed. Constructing a structural plane PD numerical model by combining the geometrical characteristics of the structural plane reconnaissance on site and the mechanical parameters of the indoor direct shear test, and analyzing the influence of the geometrical and mechanical characteristics of weak planes such as joints and fractures on the local mechanical properties of the rock mass; the method comprises the following steps of: constructing an engineering scale rock mass numerical model integrated with mechanical properties of a microscopic rock block and a microscopic structural surface by relying on field rock mass discontinuous surface distribution data and indoor test basic mechanical parameters, and finishing analysis on the influence of the overall mechanical properties of the engineering scale rock mass; and the problems of insufficient cross-scale collaboration and the like are solved.

The invention discloses a research method for determining phyllite fracture surface roughness and failure mode based on digital three-dimensional reconstruction, and relates to the technical field of rock mechanics and geological engineering, and the research method comprises the following steps: S1, collecting a specific phyllite raw stone processing sample; s2, testing physical properties of the phyllite; s3, measuring the uniaxial compressive strength of the phyllite test; s4, observing the uniaxial compression damage process of the rock through a high-speed camera; s5, establishing a uniaxial compression test numerical model of the rock through PF C, and analyzing rock fracture characteristics; s6, using a microcomputer to control a rock direct shear apparatus to apply a plurality of groups of different normal stresses to the grouped samples to carry out a direct shear test; according to the method, through experiments and analysis in multiple aspects, the characteristics of the phyllite can be accurately mastered, the behaviors of the phyllite under different stresses can be effectively predicted, the engineering safety is improved, the engineering scheme is optimized, the engineering cost is reduced, and meanwhile, a systematic, comprehensive and referential research example is provided for research in related fields.

The invention discloses a method for modifying red clay by straw fiber composite ecological cement and application thereof. The straw fiber composite ecological cement modified red clay is prepared from air-dried red clay, ecological cement, straw fiber and water. The method comprises the following steps: a, obtaining straw fiber, ecological cement and red clay raw materials; b, testing to obtain the optimal moisture content, specific gravity and liquid-plastic limit index of the red clay; c, setting a plurality of orthogonal test proportions; d, matching the proportioned dry materials, adding a proper amount of water, braising the materials for 24 hours, uniformly stirring one part of the materials to prepare a standard cutting ring sample, and uniformly stirring the other part of the materials for a planting test; and e, performing a direct shear test, a penetration test, a fracture analysis test, a soil-water characteristic curve test and a plant growth test on the cutting ring sample after the dry-wet cycle. According to the method, the shear strength, permeability resistance and water stability of the red clay can be improved, deformation and crack development of the red clay are effectively prevented, and the modified red clay obtained through the method can be applied to channel slope construction.

The invention aims to provide a large gravelly soil direct shear test device and system, and relates to the technical field of gravelly soil shear tests.A supporting plate and a shear barrel are arranged on a base, a lead screw is rotationally arranged between the supporting plate and the shear barrel, and the lead screw is driven by a motor to rotate so that the upper shear barrel can slide along the lead screw to simulate gravelly soil shear; pressure sensors are arranged on the rear wall of the upper shearing barrel and the front wall of the lower shearing barrel and can monitor the shearing force when the gravelly soil is sheared, and a displacement distance measuring sensor is arranged on the supporting plate and can monitor the horizontal movement distance of the upper shearing barrel; the hydraulic rod stretches out and draws back to control the pressing head to move downwards to compact gravelly soil in the shearing barrel, the pressing head can synchronously move along with the upper shearing barrel, and a pressure sensor is arranged below the pressing head to monitor the counter-acting force of the gravelly soil to the pressing head; a discharging port is formed in the base and located below the lower shearing barrel, the discharging port can be controlled to be communicated with the lower shearing barrel through the sliding partition plate, and therefore gravelly soil in the shearing barrels can be conveniently cleaned.

The invention discloses a large-scale visualized direct shear test device and method for geosynthetics. The device comprises a main frame, an upper shear box, a lower shear box, a normal cyclic loading system, a horizontal cyclic shear loading system, a data acquisition system and a visualized monitoring system. The direct shear test device is characterized in that the direct shear test device can perform normal and horizontal cyclic loading at the same time, and normal stress with different frequencies and amplitudes can be applied according to needs to simulate a test of the characteristics of the reinforcement-soil interface under the cyclic loading effect; one side wall of the upper shear box and one side wall of the lower shear box are transparent observation windows, and a high-speed camera and a digital image analysis method are combined, so that the shear band evolution process can be visually observed and quantitatively analyzed; the shear box is large in size, and the size effect is effectively overcome. According to the invention, the interface characteristics under the cyclic load effect in the road engineering can be reflected more truly and comprehensively, the size and the function of the shear box are comprehensive, and the interface mechanical characteristics and the interaction mechanism under various working conditions can be simulated.

The utility model provides a single-sided direct shear test device for a soil sample, which relates to the technical field of direct shear test devices and comprises two support frames, a workbench is fixedly mounted between the tops of the two support frames, and two fixing blocks are fixedly mounted at the top of the workbench. According to the utility model, the positions of the two hydraulic cylinders can be adjusted through the operation of the motor, so that the hydraulic cylinders can be vertical to the soil sample, and the hydraulic cylinders operate to apply pressure to the soil sample, so that the automation degree is high, the control is simple and reliable, the complexity and uncertainty of manual operation are greatly reduced, and the accuracy and efficiency of the test are improved; meanwhile, the pressure received by the soil sample can be observed in real time through the pressure gauge, and the value of the pressure applied to the soil sample by the hydraulic cylinder can be directly displayed, so that a tester can grasp the change condition of the pressure in real time and adjust the pressure output of the hydraulic cylinder as required, and the accurate and stable pressure is applied to the soil sample; the device has the advantages of being high in automation degree, uniform and stable in applied pressure and high in adaptability.

The invention discloses a viscous fine particle-based MICP rock fracture restoration three-dimensional discrete element simulation method, which comprises the following steps: carrying out a direct shear test on a rock sample, obtaining stress data and particle size data of the rock sample in the test process, and establishing a relation model; establishing an initial model of fine particle cementation, setting a scaling coefficient and creating boundary and contact conditions; physical attributes and geometric attributes are given to each sphere, the process of repairing rock fractures by calcium carbonate is simulated under the gravity effect, and a discrete sphere set within the boundary range is stored as a first model and placed into a particle attribute giving module; simulating calcium carbonate precipitation; gradually loading extrusion force, detecting the stability of the model by utilizing a balance force function, storing the model as a model II, and putting the model II into a shear loading module; and evaluating a reinforcement effect and judging a failure mode. According to the method, the biological rock fracture repairing effect and the numerical simulation of the damage state can be quickly and flexibly predicted at low cost.

The invention relates to a UHPC-NC interface mechanical property prediction method and system considering a size effect, and the method comprises the steps: preparing a target test piece, collecting original data through a direct shear test and a pull-out test, and obtaining a shear stress-displacement curve and a tensile stress-displacement curve according to the original data; extracting shear performance parameters and a linear relation according to the curve, carrying out fitting analysis on the shear performance parameters to obtain a shear size effect law, further defining a shear macroscopic constitutive model, and carrying out fracture mechanical quantitative evaluation on the shear performance parameters to obtain a shear macroscopic constitutive model. Deriving and constructing a prediction expression of shear resistance and a shear-displacement constitutive model according to a quantitative evaluation result; extracting tensile property parameters according to the curve, performing series analysis on the tensile property parameters to obtain an interface tensile relationship, performing probability distribution analysis on the tensile property parameters to obtain a tensile size effect law, and performing derivation according to the interface tensile relationship and the tensile size effect law to obtain a tensile property prediction expression and a tensile-fracture constitutive model.

The invention discloses a test device for testing water-salt migration and shear strength of a novel partition layer of a salinized soil roadbed under THMC coupling conditions and a use method of the test device. The device comprises a water-salt migration system, a temperature control system, a vertical loading system, a horizontal shear system and a data monitoring system. Wherein the temperature system simulates roadbed temperature difference, the water-salt system reproduces internal water-salt migration, the vertical loading simulates an upper load, the horizontal shearing system directly measures the strength of a soil sample, and the data system monitors and records moisture, salt, temperature, stress and settlement changes in the soil sample in real time. The device can simulate a complex THMC coupling environment, reveal water and salt migration, temperature stress distribution and settlement rules, and can execute a direct shear test under the condition of keeping the original state of a soil sample. On the whole, the method has high feasibility, practicability and applicability, and a powerful tool is provided for salinized soil roadbed research.

The invention provides a rapid evaluation method for shear strength of a rock structural plane under normal disturbance, and belongs to the technical field of geotechnical engineering and rock mechanics, the method comprises the following steps: S1, sample preparation and initial parameter acquisition; s2, normal disturbance direct shear test; s3, fitting test data and establishing an empirical model; and S4, rapidly evaluating the shear strength. According to the method, by introducing a normal disturbance stress parameter, an empirical calculation formula capable of rapidly predicting the shear strength after disturbance is established, and key parameters are provided for engineering design and stability analysis.

The invention belongs to the technical field of direct shear tests, and particularly provides an in-hole in-situ direct shear test device for fine particle tailings and a use method of the in-hole in-situ direct shear test device. The in-hole in-situ direct shear test device for the fine particle tailings comprises a counterweight support, a torsion device box, an inner frame body guide frame, an annular soil cutting hydraulic box, an outer frame body, an inner frame body, an inner frame body shear plate and an outer frame body shear plate, and the outer frame body is a cylindrical barrel. The use method of the in-hole in-situ direct shear test device for the fine particle tailings comprises the following steps: deploying a first oil pump, a second oil pump and a power supply on the ground, assembling the in-situ direct shear test device, and mounting a counterweight; the in-situ direct shear test device is tripped into the exploration drill hole; starting a first oil pump; starting a second oil pump; starting the power supply. According to the scheme, vertical stress and normal stress of soil sample shearing are applied to a tailing soil sample through balance weight and hydraulic pressure at the tailing sampling depth, and the cohesive force and the strength parameters of an internal friction angle of fine-particle tailings are objectively obtained.

The invention discloses a method for testing modification performance of shopping mall site soil under high water content. The method comprises the following steps: step 1, preparing a soil sample; step 2, direct shear test; step 3, disintegration test; step 4, carrying out a scale test; 5, scanning an electron microscope; step 6, ABAQUS software modeling is carried out; step 7, analyzing an experimental result; methyl sodium silicate liquid is added to improve ruin soil for ruin repair, methyl sodium silicate reacts with carbon dioxide and water in air to generate a net-shaped organic silicon resin film, the surface of a soil body structure is wrapped with the net-shaped organic silicon resin film, the anti-capillary effect can be achieved, a hydrophobic layer with excellent performance is formed, and a product of the organic silicon resin film has micro-expansibility and can be used for repairing ruins. By means of the method, pores can be blocked, the compactness of a soil body is improved, the strength of the soil body is improved, the mechanical property and the water physical property of the ruin soil are effectively improved, a step progressive repairing method is adopted, the bottom layer is repaired firstly, then the upper layer is repaired, and finally the penetration depth of the material is deepened.

The invention relates to the technical field of geotechnical engineering and geological disaster prevention, in particular to a method for testing and predicting a retaining wall of a soil-rock mixture high landfill. The method comprises the following steps: S1, sample preparation: determining soil materials with different maximum particle sizes by adopting a rejection method, a similar gradation method and an equivalent substitution method according to a field soil material gradation curve of the soil-rock mixture; s2, large-scale direct shear test: performing direct shear test on each group of samples prepared in the step 1 by using a direct shear apparatus, and determining the shear strength of each sample. According to the method, the stability of the soil-rock mixture high landfill site can be improved, indoor tests, physical models, discrete element simulation and theoretical analysis are integrated, the stability influence main cause and the instability mechanism are accurately recognized, effective prevention and treatment measures are provided, a scientific basis can be provided for safety risk assessment and site selection optimization of the stockpiling site, and the method is suitable for popularization and application. And the land reclamation technology is combined, engineering safety and environment harmony are ensured, and remarkable social and economic benefits are achieved.

The invention discloses an integrated in-situ direct shear apparatus, and relates to the technical field of geotechnical engineering testing. Comprising a bottom plate, a shear box, a supporting column arranged on the bottom plate, a bracket capable of sliding up and down along the supporting column, a guide rail arranged on the bracket, a soil body stripping device arranged on the bracket, a normal loading device arranged on the bracket and a lateral loading device arranged on the bracket, the force sensors are arranged at the output ends of the lateral loading device and the normal loading device, the displacement sensor is arranged on the support and used for measuring the displacement of the shear box, and the control system is used for controlling the lateral loading device, the normal loading device and the soil body stripping device to act and collecting and processing data of the force sensors and the displacement sensor in real time. The guide rail is used for enabling the soil body stripping device to move along the circumferential direction of the shearing box; through modular integration and automatic control, simplification of the in-situ direct shear test is realized, and the in-situ direct shear test device is suitable for occasions requiring rapid, batch and high-precision on-site soil engineering tests.

The present invention relates to an interface formwork for an ECC-gangue concrete layer in a composite concrete member and a preparation method thereof, and relates to the technical field of composite concrete members. It includes: a bottom formwork, side formworks, a steel reinforcement cage, and an anti-overflow partition board. The side formworks are installed around the top of the bottom formwork to form a frame structure with an upper opening. The steel reinforcement cage is arranged inside the frame structure, and the anti-overflow partition board is inserted into the steel reinforcement cage to equally divide the inside of the frame structure into two parts. The present invention can be used for pouring a "Z"-shaped member for a direct shear test on one side. The formwork is convenient to assemble, the process is simple, and the design of the anti-overflow partition board can effectively prevent concrete overflow while satisfying the passage of steel bars through the interface when the pouring times of the concrete on both sides are inconsistent, ensuring the quality of member pouring.

The loess shear strength in-situ testing device comprises two underframe rods which are equal in height and are arranged in parallel at an interval, a mounting frame is arranged at the tops of the two underframe rods, a probe rod is longitudinally mounted on the mounting frame, the probe rod is driven by a driving mechanism to move up and down, ground anchors are arranged on the two sides of the bottom of each underframe rod, and the lower portion of the probe rod is connected with a force measuring steel bar meter. The output end of the force-measuring reinforcement meter is electrically connected with the input end of the shear strength data acquisition instrument, and the lower end of the force-measuring reinforcement meter is connected with an isosceles right triangle-shaped pressure-bearing plate with a flat plate surface. According to the utility model, the bearing plate at the bottom of the feeler lever abuts against a specified detection position of a to-be-detected area and applies a vertical force downwards, the force measuring reinforcement meter transmits stress change to the shear strength data acquisition instrument, and the shear strength data acquisition instrument automatically obtains shear strength parameters of the specified detection position; the test principle is basically the same as that of a direct shear test, and related principles can be directly utilized; the disturbance to the soil body is smaller than that of an indoor test, and the result is more reliable.

This invention discloses a combined shear-resistivity testing device and method for soil-rock mixed fillers, belonging to the field of geotechnical engineering testing technology. It addresses the shortcomings of existing combined testing methods, such as unstable contact resistance, fluctuating electrical signals, and asynchronous data. The device includes a direct shear test, resistivity test, and data acquisition and control system. The shear test chamber has a multi-layered composite structure integrated electrode embedded in its inner wall, coupled with an array of spring needles, and features a stress-driven electrical connection and hardware synchronous triggering structure. The method completes the test through steps including sample preparation, system initialization, stress-driven electrical connection establishment, and synchronous triggering of the combined test. This invention achieves synchronous and accurate acquisition of shear mechanics and resistivity data, enabling real-time non-destructive characterization of the internal structural damage evolution of the sample, significantly improving testing accuracy and stability, and providing reliable technical support for the mechanical research and engineering applications of soil-rock mixed fillers.

The utility model belongs to the technical field of sandy soil sampling, and particularly relates to an undisturbed soil sampling device suitable for an indoor direct shear test, which comprises a plain-end cutting ring, a cutting ring with a blade, a sleeve, a rectangular cutting plate, a cutting plate with a blade, a circular cover plate and a flat-angle cover plate. Then the cutting ring and the sleeve are pushed into soil, the upper surface and the lower surface of the cutting ring are scraped to be flat through a cutting plate, the cutting plate is fixed up and down through bolts, sealed storage is conducted, after the cutting ring is sent to a test room, the bolts are removed, cutting ring samples with cover plates are placed into a shear box, meanwhile, adhesive tape between the cutting ring samples is cut open through a small knife, and a test is prepared; according to the device, disturbance to surrounding sandy soil is reduced, the integrity and accuracy of the sampling process are ensured through the cutting and collecting functions of the sampling device, and reliable basic data support is provided for sandy soil research.

The invention discloses a soil-rock interface undisturbed sample torsional shear test device which comprises a base, a supporting frame and a test assembly, the supporting frame is fixedly installed on one side of the upper portion of the base, the test assembly is movably installed on the inner side of the supporting frame, the supporting frame is stably installed and used through the base, and the test assembly is installed and used through the supporting frame. A test assembly is arranged to be used for a torsional shear test, and the test assembly comprises a test box, a telescopic air cylinder, a lifting disc, a first motor, a first rotating plate, a second motor, a second rotating plate and a torque sensor. According to the invention, upper and lower groups of motors are arranged to perform upper and lower groups of tests on a test sample, and a torque sensor is arranged to ensure uniform stress distribution on a shear surface, so that a common stress concentration phenomenon in a traditional direct shear test is avoided, and the accuracy of a test result is improved; the device can be used for treating undisturbed undisturbed soil samples, and the original structure and properties of a soil body are reserved.

The application discloses a vertical load device for large-scale direct shear test in situ, which mainly comprises a crossbeam, a counterweight, an anchor, a counterweight plate, a roller, a first jack, a pressure sensor and a sliding module. During the test, a hard layer is first laid on the soil on both sides of a sample, and then the counterweight and the crossbeam are erected on the hard layer; during the erection, the locking block and the locking block are locked to avoid the movement of the counterweight and the crossbeam again, thereby affecting the shear test; then, a shear box is sleeved on the sample, and a third steel plate and the first jack are placed on the shear box; then, the sliding module is installed between the first jack and the crossbeam, and finally, the force of the first jack pushing the crossbeam upward is adjusted to meet the requirement of different loads on the sample. In addition, after the completion of the current experiment, the roller is released to push the counterweight and the crossbeam to the next sample, and the next sample can be tested, so that the operation is simple, convenient, flexible, fast and the like.

The invention discloses a composite foundation design method based on the influence of soil around a pile on the strength of a gravel pile and application, and the design method comprises the steps that each soil layer is subdivided, and the relation between the undrained shear strength value and the depth of each subdivided soil layer is recorded; performing statistics on the data by adopting a mean square error method according to the dynamic sounding hammering number data of the gravel pile, so as to obtain the dynamic sounding hammering number N of each subdivided soil layer; counting the statistical relationship between the undrained shear strength value of each soil layer and the dynamic sounding hammering number N of the gravel pile, and evaluating the compactness of the soil layer; crushing gravel with different compactness through a large direct shear test or a large triaxial test, and establishing a relationship between the different compactness of the gravel and an internal friction angle; establishing an empirical relationship between the strength of the soil around the pile and the value of the internal friction angle of the gravel; and composite foundation parameters are selected according to the subdivided soil layer parameters. The internal friction angle parameter of the gravel pile can be obtained in a layered mode according to the distribution of the soil layer, and the actual mechanical property can be better reflected.

The invention discloses an automatic penetration type miniature in-situ direct shear apparatus. The apparatus comprises a support frame, and a first driving module, a test module, a soil body cutting module and a sensor module which are arranged on the support frame, the support frame is anchored on the ground; the first driving module is fixed with the test module; a moving end of the first driving module is connected with the test module; the test module comprises a shell, a second driving module, a shear box and a valve; the shell is connected with the moving end of the first driving module; the second driving module is fixed in the shell; the upper end of the shear box is connected with the moving end; the valve is positioned at the lower end opening of the shear box; the two soil body cutting modules are symmetrically arranged at the lower end of the shell and are opened and closed through a driving motor to cut a soil body; the sensor module is used for collecting pressure data and displacement data in the test process. The test module can penetrate into a soil body in a narrow space or under a special geological condition, a direct shear test is completed in the in-situ soil body, disturbance in the sampling process is reduced, and wide application prospects are achieved.

The present application relates to the cross technical field of geotechnical engineering and machine learning, especially a concrete-sand interface bearing capacity prediction method and system based on machine learning, the method comprising the following steps: obtaining core input parameters to obtain multi-working condition test variables; preparing a concrete sample, constructing a multi-working condition direct shear test through a test device; carrying out the multi-working condition direct shear test and collecting data during the test to obtain a multi-dimensional original data set; obtaining a modeling data set according to the multi-dimensional original data set, combining machine learning to construct a concrete-sand interface bearing capacity prediction model; performing model optimization and generalization capability verification to obtain a bearing capacity prediction optimization model; obtaining a bearing capacity prediction result according to the bearing capacity prediction optimization model, and obtaining a characteristic influence analysis result. The present application studies the concrete-sand interface shear resistance bearing law under the coupling action of multiple factors, and provides a scientific basis for the design and construction of geotechnical engineering.

The invention belongs to the field of rock mechanical property evaluation, and particularly relates to a rock structural surface shear brittleness index obtaining method and a shear brittleness evaluation method. And carrying out a direct shear test on the rock structural surface to obtain a shear stress-displacement whole-process curve, calculating according to the shear stress-displacement whole-process curve to obtain a pre-peak brittleness parameter S1 and a post-peak brittleness parameter S2, and multiplying the pre-peak brittleness parameter S1 and the post-peak brittleness parameter S2 to obtain the shear brittleness index SI of the rock structural surface. According to the method, the shear stress rise rate in the pre-peak loading stage, the shear stress drop amplitude in the post-peak stage and the relative displacement in the residual deformation stage are comprehensively considered, the whole-process shear deformation characteristics of the rock structural surface can be comprehensively reflected, and the required parameters are easily measured through a mechanical test.

This utility model relates to the field of rock mechanics testing technology, and in particular to a cylindrical rock core direct shear test device. The cylindrical rock core direct shear test device includes a base plate, two sets of support plates, a support beam, and two sets of linear guide rails; a control box, installed on the outer wall of the support plates; two sets of guide rods, each set installed in a through slot in one of the two support plates, with a lifting plate slidably mounted on each set of guide rods. An upper shear sleeve is fixedly mounted on the lifting plate, and a positive pressure mechanism is installed on the support beam directly above the upper shear sleeve; a sliding frame, slidably mounted on the two sets of linear guide rails, with a connecting column fixedly mounted at the top of the sliding frame, and a lower shear sleeve fixedly mounted at the top of the connecting column. A clamping assembly for holding the cylindrical rock core is mounted on the lower shear sleeve. The cylindrical rock core direct shear test device provided by this utility model has the advantages of convenient loading and unloading and accurate testing.

The invention discloses an in-situ drilling vertical direct shear test device suitable for a soft soil area. The in-situ drilling vertical direct shear test device comprises a counter-force bracket, a soil sample in-situ shear cylinder, a worm gear elevator and a data acquisition and transmission control device, a hollow steel cylinder is arranged at the lower end of the soil sample in-situ shearing cylinder, and the diameter of the steel cylinder is the same as that of a reconnaissance drill hole; two soil body vertical direct shear boxes capable of extending out of the hollow steel cylinder are symmetrically arranged in the hollow steel cylinder; the hydraulic ejector rod is used for pushing outwards; strain gauges are arranged on the back surfaces of a bottom plate and a side plate of the soil body vertical direct shear box and are connected with a data acquisition and transmission control device; a rod piece is arranged at the upper part of the soil sample in-situ shearing cylinder, the upper end of the rod piece is connected with a worm gear elevator, and the worm gear elevator is fixed on a counter-force bracket. According to the device, the natural state of a soil body structure is kept to the maximum extent, it is guaranteed that the stress state of a soil body is not changed, mechanical parameters of a current reconnaissance soil layer are tested in situ, reconnaissance design work of geotechnical engineering can be guided, and the device has the advantages of being convenient to carry and easy to operate.