109 results about "Soil stress" patented technology

The invention discloses a piezoresistive high-frequency dynamic soil stress sensor and a fabricating method thereof. The sensor comprises a sensor shell (7), a stress sensitive component, a signal conditioning amplifying circuit (11) and a leading-out cable (13), and the stress sensitive component comprises a structure formed by a substrate (1), an insulating isolating layer (2), a strain resistor (3) and an insulating protection layer (5), and is connected to a clamped step (18) at the front end of the sensor shell (7) in a sealed manner through high borosilicate glass (6). The stress sensitive component integrates the strain resistor (3) and an adjusting resistor (19), so that the size is effectively reduced, machining process is simplified, manufacturing cost is lowered, mass production is easy to realize, and cost-performance ratio and market competitiveness of products are improved.

The soil stress is composed of shell, stress-sensing module (SSM), and output cable. An elastic body capable of sensing stress is fixed at front end of shell of sensor. A clamped sidestep with structure of hole is formed inside the shell of sensor. Being fixed at end face of the clamped side step, SSM is silicon piezoresistance type module with structure of Wheatstone bridge. Fluid pressure medium for propagation is filled in a cavity formed between the end face of the clamped sidestep and the elastic body. Through an adapter plate, a lead out cable, a signal rectification circuit, the intraconnection of SSM is connected to the external output cable. Introducing mature silicon piezoresistance type sensing element to mechanics research area of soil stress, the invention fabricates piezoresistance type stress sensor. Features are: volume-produce by IC technique, good consistency and low frequency characteristic, simple signal process, and miniaturization.

The invention provides a CFG pile composite roadbed rubber spacer static load testing device and method. The method comprises the steps that according to the embankment design condition, the punching shear failure angle method is adopted to calculate loads of embankment filling acting on piles and soil between the piles respectively, and pile soil bearing loads and the pile soil stress ratio are obtained; differential settlement of the piles upwards piercing into the spacer amount and differential settlement of the piles upwards piercing into composite foundation pile soil are respectively calculated, the pile piercing amount is comprehensively determined, and according to the table 1, rubber spacers are selected. Arranging is carried out according to the CFG pile composite roadbed rubber spacer static load testing device, and the steps of gradation loading, steady judgment, final load control, data recording and the like are carried out reference to existing specifications and design. According to the device and method, rubber spacers are determined in a mode that load-bearing compression deformation of the rubber spacers is close to the loads, borne by pile bodies, in the actual station, of the upward piercing amount of the spacer amount, a load transfer mechanism of the actual working condition can be simulated, the aim that embankment loads are distributed by the rubber spacers is achieved, and the pile soil stress ratio conforming to the reality can be achieved.

The invention discloses a soil in-situ shear resistance tester, which is characterized in that: the soil in-situ shear resistance tester comprises a supporting device, a shearing device, a sensing device, a driving device and a data acquisition and analysis device, wherein the supporting device is used for fixing the driving device; the shearing device is used for directly acting on the soil to make the soil stressed uniformly; one end of the sensing device is connected with the shearing device, while the other end is connected with the driving device; the sensing device is used for outputting electric signals proportional to traction; the driving device drives the shearing device to perform destructive tests at a linear speed required by shear tests; and the data acquisition and analysis device is used for recording the maximum value of the traction in the horizontal direction according to the electric signals, and the soil shear resistance is calculated according to the shear area of the shearing device.

The invention belongs to the field of research of buffer material multi-field coupling performances in high-level waste geological disposal and in particular relates to a sensor arrangement structure and a method in a buffer material multi-field coupling experiment bench. The invention aims to provide necessary conditions for successfully constructing a buffer material thermal-water-force-chemical multi-field coupling large experiment bench and indicating behaviors of the buffer material under the multi-field coupling condition. According to the structure and the method, three different monitoring areas are divided in a compacted bentonite block layer from bottom to top according to the position of a heater in the experiment bench, different monitoring layers are finely divided in each monitoring area, and the monitoring layers are perpendicular to a cross section of a vertical axis of the experiment bench, wherein two monitoring layers are divided in a bottom monitoring area, four monitoring layers are divided in a middle monitoring area, two monitoring layers are divided in an upper monitoring area, a displacement sensor needs to penetrate through multiple monitoring layers, and a soil stress sensor, an interstitial hydraulic pressure sensor, a temperature sensor, a temperature and humidity sensor and an electrochemical corrosion sensor are positioned in the monitoring layers.

The invention discloses an effective pile length researching simulation test box for a variable parameter super-long pile. The effective pile length researching simulation test box comprises a test pile, a bearing table, a bottom plate, a conduction column, springs, a jack, a flexible loader, a test box body, a partition plate, a counter-force beam and a counter-force frame, and further comprises an optical fiber sensor, soil stress detectors and a test pile body variation layer. By means of the effective pile length researching simulation test box, tests of a super-long pile foundation under certain control conditions can be completed; the action mechanism of the super-long pile foundation is explored, and the effective pile length phenomenon is researched; the test pipe body is a pile capable of being assembled and disassembled, the outer layer of the pile body is wrapped by the test pile body variation layer, various pile body parameters such as the diameter of the pile and the friction and resistance coefficients between the pile and soil, the diameter of the pile end and other parameters can be varied, and the mutual variation of various parameters between the super-long pile and the soil body can be basically covered. Theoretical guidance and test data support are provided for the design of the super-long pile foundation, and the application and practice risks of the super-long pile foundation are lowered.

The invention discloses a determination method for a critical plastic yield-point and an initial elastic modulus of a soil stress-strain curve. The method comprises three parts, i.e., triaxial test of soil, determination of a critical plastic yield-point and determination of an initial elastic modulus; the triaxial test is a traditional triaxial test, and a sample to be tested is cylindrical; the determination of the critical plastic yield-point is carried out through determination of a linear correlation coefficient of a fitting straight line; the initial elastic modulus is obtained through the slope of the fitting straight line. The determination method provided in the invention has the advantages of simple test, concise calculation and convenient operation, and has an important meaning for research on establishment of soil constitutive models, engineering numerical simulation, evaluation of foundation stabilization, ground settlement, especially settlement caused by small deformation, etc.

The invention provides a soil anisotropic mechanical property research idea and method from the microscopic point of view by developing a horizontal loading program and a micro-mechanical parameter monitoring program through a particle discrete element unit method. The method includes the steps of (1) obtaining stress-strain curves and related mechanical parameters of cohesionless soil according to laboratory tests; (2) establishing a plane biaxial specimen to simulate soil original anisotropy according to micromechanics parameters determined in a particle flow biaxial test in step (1); (3) establishing a plane biaxial specimen to simulate soil stress anisotropy according to the micromechanics parameters determined in the particle flow biaxial test in step (1); (4) comparing and analyzing expression rules of soil original anisotropy and the soil stress anisotropy to obtain the difference and relation between the two kinds of anisotropy and finding out microscopic mechanisms of the production of the two kinds of soil anisotropy. The soil anisotropic mechanical property research idea and method provides a new idea for the cohesionless soil anisotropic mechanical property numerical simulation by using the advantages of the particle flow discrete element method in the research of the particulate material microstructure.

The invention provides a plant root secreta generation and collection device and a collection method thereof. The device comprises a plant growth device, a root growth guiding device and a root elution and secreta collection device. The root growth guiding device comprises a net structure and a plastic separator plate. The collection method is a plant root secreta collection method under soil stress under natural conditions and does not interfere root growth and damage a rhizosphere environment. The collection method comprises root secreta effective expression without outside interference after single pathogen infection and monitoring of root secreta change after rhizosphere pathogen infection.

The invention discloses a self-balancing type multi-loading-path one-way shearing box for a pile-soil test and belongs to the technical field of geotechnical engineering tests. A loading part of the device can change positions to apply static or quasi-static loads such as pulling, pressing and pushing under different loading paths, soil stress diffusion and attenuation can be simulated through a semi-shearing device, and the influence of boundary conditions is reduced so as to achieve the purpose of reducing the size of the model. The device is composed of a reaction frame, a loading device, an angle steel model box and the semi-shearing device. The model box is used for bearing piles and soil and is a main place for pile-soil interaction. The one-way shearing device realizes the one-way shearing of a soil body, unifies experimental boundary conditions and actual boundary conditions, reduces the size of the model while improving the test reliability, and reduces financial and materialresource consumption. The reaction frame and the loading device are used for applying loads, multiple combination modes are achieved, the loading position and angle can be adjusted, and the multi-pathloading can be achieved.

The invention provides a novel power lateral confinement compression test device. The novel power lateral confinement compression test device comprises a compression apparatus and a displacement measuring module, wherein the displacement measuring module is used for monitoring the position change of a sample. The novel power lateral confinement compression test device is characterized by also comprising a vertical load loading module, a water level fluctuating module, a dry and wet circulating module and a sample deformation monitoring module; the vertical load loading module is arranged at the top part of the compression apparatus, and is used for providing a vertical load for the sample; the water level fluctuating module is connected with one side of the compression apparatus, and is used for simulating a tide load; the dry and wet circulating module is connected with the bottom part of the compression apparatus, and is used for simulating rainfall and evaporation; the sample deformation monitoring module is arranged at the side of the compression apparatus, and is used for observing and recording the deformation of the sample in the experiment process. The novel power lateral confinement compression test device has the advantages that in a lateral confinement compression test, multiple power loads can be loaded to the sample, the complicated conditions in the project practice are simulated, the soil stress state is truly reflected, and the change of compression characteristic of the soil under the action of external load is measured.

The invention discloses a method for evaluating the soil stress corrosion cracking of a high-strength pipeline. A technology for calculating the remaining strength of the pipeline under the soil stress corrosion is given through aiming at the soil stress corrosion characteristic of the pipeline and considering the interaction of defects. The interaction of the defects is an important part in the complete assessment of the pipeline. The method provides technical support for assessing the integral service life and the remaining service life of the soil stress corroded pipeline, and is of great significance to assessing the safety or not of the pipeline, preventing pipeline failure and guaranteeing safe running of the pipeline.

The invention discloses a method for pre-estimating post-construction settlement of a composite road foundation by a static load test. The method comprises the steps: obtaining a value of the pile-soil stress ratio; conducting a multi-stage loading test to the maximum test load, and then judging stability; after stability judging, continuing a sustaining load delaying test; determining relevant parameters for pre-estimating the post-construction settlement by a laboratory test and engineering experience; according to test data including the pile-soil stress ratio, settlement parameters and the relevant parameters, predicting the secondary consolidation coefficient of soft soil, pre-estimating post-construction secondary consolidation settlement, and calculating post-construction primary consolidation settlement; converting a measured settlement value of a plate load test to an immediate settlement value of the actual working condition of the composite foundation, and integrally pre-estimating the total post-construction settlement of the composite foundation according to the immediate settlement value of the actual working condition, the primary consolidation settlement and the secondary consolidation settlement. The method develops a new static load test technology capable of pre-estimating the post-construction settlement of the composite foundation and provides a new idea for the further development and benefit exerting of the static load test technology for the composite foundation.

The invention discloses a multifunctional model test pile which comprises a pile top, a pile body, a tensile retaining ring, a pull ring, miniature earth pressure cells and a pile end. The pile top is provided with a spherical hinge and a wiring connection piece, the spherical hinge and the wiring connection piece are connected with the pile body, a plurality of grooves are reserved in the pile body, the grooves are internally provided with the miniature earth pressure cells, the tensile retaining ring is arranged on the pile body in a sleeving mode and can be fixed, the pull ring is arranged on one side of the tensile retaining ring, the other end of the pile body is internally provided with a vertical force sensor, the force sensor is connected with a pile tip through a force transfer rod, a sponge ring is arranged in a gap between the pile tip and the pile body, and the measurement wires of the miniature earth pressure cells and the force sensor are guided out of circular holes in the wiring connection piece from the interior of the pile body. By means of the model pile, the earth pressure along a pile and the pile end resistance of the pile in a soil bed can be measured, the problem of interference of an original pile soil stress field through a general test and measurement mode is solved, a vertical load test, a horizontal load test and an anti-drawing test of the pile can be simulated, and the multifunctional model test pile has the advantages of being high in accuracy, wide in application range and easy and convenient to operate.

The invention discloses a group anchor effect model test device and a detection method. The device comprises a model box, a simulated stratum system is arranged in the model box, a group anchor systemis arranged on one side of the model box, the group anchor system penetrates through the simulated stratum system in the model box, a load loading system is arranged above the model box, an anchor rod detection system is arranged on the group anchor system, and the anchor rod detection system is connected with a detection control system. According to the invention, an existing group anchor detection device and detection method are improved, and the test precision is improved; the research on influence factors of the group anchor effect is expanded and perfected, for example, the position relation between a sliding surface and an anchor rod, the spatial position form between the anchor rods, the angle, the vertical distance and the like, the soil stress form and other factors are integrally considered such that the group anchor effect coefficient obtained through a test is more accurate, and the invention provides a group anchor effect detection method based on an intelligent jack/intelligent loading system and dynamic action such as vibration load.

The invention relates to a typical geology PHC pipe pile construction method. The method includes the following steps: (1) matching piles, according to typical geological exploration data, selecting afirst joint of pipe pile and a second joint of pipe pile; (2) first time of piling, firstly, causing the bottom end of the first joint of pipe pile to evenly press natural ground so that the first joint of pipe pile is struck to a bearing stratum of typical geology; (3) pile splicing, welding the second joint of pipe pile together with the first joint of pipe pile after an interval of over 8h; (4) second time of piling, which is carried out immediately after pile splicing until the second joint of pipe pile is caused to even the natural ground; and (5) pile following. Therefore, the method conducts second time of piling/pressing pipe piles after the generated soil stress is completely vanished, in a time interval after the first time of piling/pressing piles, and can effectively strike and press the pipe piles into the bearing stratum of typical geology, thus solving the problems of the prior art. The method is simple and convenient for operation.

The invention relates to a pile lateral friction resistance test device and method for simulating an indoor soil stress state around a pile, and belongs to the field of foundation engineering and foundation treatment. The pile lateral friction resistance test device includes a pile-soil action mechanism, a pressure chamber loading mechanism and a data collection mechanism, the pile lateral friction resistance test device and method aim at restoring the actual stress state of soil around the pile in a stratum, overburden pressure and horizontal lateral pressure are simultaneously applied to thesoil around the pile through two sets of hydraulic devices, and under the condition of vertical loading of the top of the pile, pile lateral friction resistance at any depth in one soil layer is measured. A relation curve between the pile lateral friction resistance and displacement of a pile body is measured to analyze performance of the pile lateral friction resistance with the displacement ofthe pile body, an ultimate lateral friction resistance value of the soil layer at any depth is obtained accurately, the problem of reasonable value of pile foundation lateral friction resistance in current engineering practice design is solved, and an important parameter basis is provided for valuing lateral friction resistance of pile foundation engineering design.

The invention provides a supporting and fixing device for fixing a GNSS instrument. The supporting and fixing device comprises a main telescopic rod and a lower supporting device. The GNSS instrumentis installed at one end of the main telescopic rod, the other end is connected with the lower supporting device; the lower supporting device comprises four branch telescopic rods which are evenly distributed in the circumferential direction of the main telescopic rod. A supporting structure is arranged at the free end of each branch telescopic rod. The device is convenient to carry, easy and convenient to assemble and disassemble, retractable, more flexible to use, capable of being leveled, capable of freely adjusting the height of the instrument and capable of monitoring factors such as windpower and wind direction and soil stress state in real time; meanwhile, compared with the traditional PVC pipe, the overall stability of the device is better through the installed hole expanding and soil expanding impact grabbing cone.

The invention provides a method for acquiring the pile-soil stress ratio of a pile-supported roadbed under a particle crushing condition. The method comprises the following steps: determining a particle damage index Br; Determining a soil body particle size coefficient nd according to the particle damage index Br; Determining the arch height hc and the arch angle alpha h of the soil arch accordingto the soil particle size coefficient n; And determining the pile-soil stress ratio of the pile-supported roadbed according to the arch height hc and the arch angle alpha h of the soil arch. The method for obtaining the pile-supported roadbed pile-soil stress ratio under the particle crushing condition can determine the load sharing condition of the pile-supported roadbed pile-soil-network, can be used for accurately calculating post-construction settlement of the pile-supported subgrade, can reduce subgrade diseases caused by soil arch damage, and save the line operation and maintenance cost.

The invention discloses a soil stress-strain relationship determination method based on an improved LSTM deep learning method. The determination method comprises the following steps: preparing soil samples with different physical and mechanical parameters; establishing an original data set of stress and strain; performing normalization processing on the original data set; establishing a four-layer LSTM deep learning network, and determining a hidden layer node number Nh, an activation function and a cost function J; determining an initial weight matrix and a vector of the LSTM deep learning network and an initial parameter of a hybrid activation function; updating the weight matrix by using a modified Adam momentum gradient descent algorithm, determining a cost function descent amplitude Jd, and updating an activation function parameter; and repeating iteration until the cost function J of the LSTM deep learning network is smaller than a preset value or reaches a preset number of iteration training times Iter. According to the determination method, the nonlinear relationship between the stress and the strain is extracted and determined from the experimental data, and the time-dependent characteristics of the stress-strain behavior of the soil body can be considered. The determination method is simple, practical and convenient to popularize, and has great application value.

A single pile calculation method based on combination of finite element software and a load transfer method comprises the following steps that 1, a soil body geometric model is established according to a geological exploration report, and the stress change process of each soil layer under the action of ground surface loading is calculated; 2, extracting soil effective stress and settlement data corresponding to a certain moment from a finite element calculation result; and 3, the axial bearing response of the pile foundation at the given moment is calculated through a load transfer curve method. The method aims at solving the problem that in the prior art, the influence of the short-term effect and the long-term effect of soil stress and settlement changes on the axial bearing capacity of a single pile under the heaped loading effect is difficult to calculate.

The invention discloses a pile supported reinforced embankment pile-soil stress determining method. The method comprises the following steps that (10) parameters are obtained, wherein physical parameters of a pile supported reinforced embankment are obtained and comprise the pile length, the pile distance, the pile cap size, the embankment earth filling height, the reinforced body grating position, the embankment top face additional load and the like; (20) the pile top additional pressure is calculated, wherein based on the reinforced embankment buckling failure mode, according to the reinforced body arranging position, the pile top additional pressure is calculated; (30) the pile top distributed load is calculated, wherein according to the pile top additional pressure and the pile top distributed load in a non-reinforced embankment, the pile top distributed load is calculated; and (40) earth-among-pile counter-force calculation is carried out, wherein according to the embankment totalload and the pile top distributed load, the earth-among-pile counter force is calculation. According to the pile supported reinforced embankment pile-soil stress determining method, based on the embankment failure mode, a reinforced body arranging manner is considered in the meantime, and the result is more accurate.