18 results about "Friction angle" patented technology

The present application belongs to the technical field of oil and gas field exploration and development, and discloses a method, device and method for establishing a strike-slip fault activity prediction model. The method for establishing the prediction model comprises: extracting the horizontal maximum principal stress, the minimum horizontal principal stress and the vertical stress in a present-day stress model based on a fracture-vug three-dimensional carving model; calculating a normal stress model and a shear stress model from the horizontal maximum principal stress, the minimum horizontal principal stress and the vertical stress; calculating a criterion internal friction angle model from the normal stress model, the shear stress model and a roughness model; and subtracting the data in the criterion internal friction angle model from the data in the shear stress model to obtain the strike-slip fault activity prediction model. The present application can more accurately establish a complex strike-slip fault activity prediction model that meets the needs of exploration and development production.

The application discloses a ship lock foundation pit confined water control method and device based on soil body shearing strength, and relates to the technical field of ship lock engineering, wherein the method comprises the following steps: calculating the confined water head, the overlying impermeable layer thickness and the initial gushing safety coefficient according to the geological survey data and the foundation pit excavation bottom surface elevation; calculating the soil body shearing strength based on the pre-acquired cohesion and internal friction angle of the overlying impermeable layer soil body; and further calculating the corrected gushing stability safety coefficient. When the corrected gushing stability safety coefficient is less than the preset gushing stability threshold, it is determined that the ship lock foundation pit engineering does not meet the gushing stability requirement, the impermeable layer soil body reinforcement construction parameter is determined, and after construction is performed according to the impermeable layer soil body reinforcement construction parameter, the ship lock foundation pit is subjected to permeation inspection. The application solves the technical problem of high cost of the water interception curtain scheme or the deployment of the water pumping well scheme used by the ship lock foundation pit engineering in response to the imbalance of the confined water in the related art.

This invention provides a method, system, equipment, and medium for calculating the heave stability of a circular shaft structure. The method includes: determining the basic parameters of the circular shaft structure, including the shaft diameter, excavation depth, retaining structure embedment depth, soil cohesion, internal friction angle, soil weight, and uniformly distributed ground load; calculating the bearing capacity coefficient and its susceptibility based on the basic parameters; dividing the sliding soil at the bottom of the circular shaft structure into a Rankine active zone, a Rankine passive zone, and a transition zone, and determining the geometric parameters of these zones; determining the external influence width based on the basic parameters and geometric parameters; and calculating the heave safety factor of the circular shaft pit using a formula based on the basic parameters, bearing capacity coefficient, and external influence width. This invention can determine the heave safety factor of a circular shaft pit, and the determined safety factor better reflects the actual situation.

The application discloses a method for obtaining soil strength indexes based on soil layer geophysical prospecting data, and comprises the following steps: S1, obtaining the test depth and equivalent shear wave velocity of different measuring points in a target site; obtaining the drilling samples of each measuring point at the corresponding depth, obtaining the corresponding internal friction angle and soil type; preprocessing the collected data to obtain a comprehensive data set; S2, selecting the test depth and equivalent shear wave velocity in the comprehensive data set as basic features, constructing derived features, performing feature standardization, and obtaining a data set; dividing the data set into a training set and a test set; S3, based on the training set obtained in S2, optimizing and training the soil classification model and the internal friction angle prediction model; S4, obtaining the soil strength index internal friction angle based on the soil classification model and the internal friction angle prediction model obtained by the training in S3. The method of the application realizes high-precision prediction of soil strength indexes by constructing derived features and introducing physical range constraints.

This invention discloses an evaluation model construction, stability evaluation method, and system for a dip-slope with alternating soft and hard joints. The process includes: first, collecting test data from multiple sets of rock joint shear tests (both soft and hard joints); then, using all the collected test data, fitting coefficients are obtained in a joint shear strength prediction model, and a joint shear strength prediction model based on the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, and the normal stress is constructed using these fitting coefficients; subsequently, based on the joint shear strength prediction model and combined with a simplified slope mechanics model, a safety factor evaluation model based on the basic friction angle of the joint surface, the average shear undulation angle, the joint strength ratio, the bedding plane dip angle, the bedding plane thickness, and the rock mass unit weight is derived. This constructs a safety factor evaluation model that considers both the joint surface morphology characteristics and the strength differences between the upper and lower walls of the dip-slope with alternating soft and hard joints.

The application provides a coal mine roadway surrounding rock stability classification method and device, comprising, obtaining the original rock ground stress field data of a target roadway area, including the size and direction of the maximum horizontal principal stress, the minimum horizontal principal stress and the vertical stress; determining the mechanical parameters of the target roadway surrounding rock, the mechanical parameters including the uniaxial compressive strength, the cohesion and the internal friction angle; calculating the plastic zone range of the roadway surrounding rock based on the original rock ground stress field data and the mechanical parameters of the surrounding rock; constructing a comprehensive stability classification index, the index being formed by the product coupling of the stress intensity ratio, the plastic zone control coefficient and the stress direction correction coefficient; dividing the roadway surrounding rock into five stability levels according to the numerical range of the comprehensive stability classification index, and matching the corresponding support form and parameters based on the surrounding rock state characteristics corresponding to each level. The application can improve the accuracy and objectivity of the surrounding rock stability classification, and provide a scientific basis for the differentiated support design of the coal mine roadway.

The present application relates to a kind of transmission line excavated foundation uplift bearing capacity design method, by the equivalent straight line AB of excavated foundation uplift soil mass slip surface, construct straight line slip surface model, deduce a kind of excavated foundation uplift bearing capacity calculation formula from straight line slip surface model, the formula only contains 3 unknown parameters, respectively, according to the equivalent internal friction angle of equivalent internal friction angle excavated foundation bottom diameter D and straight line slip surface model height h that the cohesion and internal friction angle in geology are equivalent according to shear stress equivalence principle, calculation is simple and convenient for engineers to use, by the classification of equivalent internal friction angle, compile into bearing capacity table, for engineering personnel to use, provide great convenience for engineers.

This invention discloses an intelligent monitoring method for foundation pit slopes, belonging to the field of foundation pit monitoring. The method includes: deploying vibration sensors and reference wells in the stable soil area of ​​the slope; dividing the slope into diagnostic sections and soil layer sub-units; and using a reference slip surface to divide the stable area and the area to be diagnosed. A standard excitation device, in conjunction with vibration sensors, is used to calculate the reference wave velocity of each soil layer and the representative wave velocity of each area to be diagnosed. A feature vector containing representative wave velocity, variance, and soil layer coding is constructed and input into a pre-trained soil parameter model. The equivalent cohesion and internal friction angle of each area are output in real time. Based on the reference slip surface, a limit equilibrium equation considering slope geometry, top load, and slope protection structure design anti-sliding force is established, and the overall safety factor of each diagnostic section is iteratively solved. Finally, based on the comparison between the safety factor and a preset threshold, a graded load control decision is automatically generated, realizing quantitative and intelligent proactive control of foundation pit slope stability.

The application provides a method for determining the rock arch resistance height of a soft and hard alternating stratum tunnel and a firmware chip, relates to the technical field of tunnel engineering stability analysis and safety design, can combine the resistance failure mechanism of the key hole top part of the soft and hard alternating stratum tunnel, respectively consider the mechanical properties such as the elastic modulus, the cohesive force, the internal friction angle, the joint strength and the non-constant strength parameters of the soft layer and the hard layer, accurately depict the sequence characteristics and the spatial distribution of the soft and hard alternating stratum, so as to more truly reflect the load transmission path, the stress distribution law and the potential failure mode, and significantly improve the engineering fitting degree and the reliability of the calculation result. The application realizes the quantitative analysis of the supporting effect, takes the supporting stress as a clear external force component into the energy balance system, can quantitatively evaluate the influence of different supporting stresses on the rock arch resistance height, and provides a theoretical basis and a practical tool for the fine design and economic optimization of the supporting scheme.

This application discloses a method and system for predicting the spatiotemporal variation law of borehole shrinkage in compaction piles, relating to the fields of foundation treatment and geotechnical engineering. The method includes: acquiring data such as the depth of the pile borehole to be tested; establishing functional relationships between peak cohesion, peak internal friction angle, residual cohesion, and residual internal friction angle with respect to water content based on experimental data; establishing a softening constitutive relationship based on the evolution of strength from peak to residual based on cumulative plastic shear strain; determining the far-field lateral stress by combining depth, soil weight, and at-rest earth pressure coefficient, and constructing a three-zone stress field around the pile borehole comprising a residual zone, a softened zone, and an elastic zone; further constructing a system shrinkage coefficient based on the relationship between the stress state at the borehole wall and the viscoplastic strain rate, and establishing an evolution equation for the borehole radius with respect to time, depth, and water content; and calculating the variation of the pile borehole radius with time and depth within a target time period based on the evolution equation. This method achieves unified calculation of the shrinkage process under the combined action of multiple factors.

The present application relates to a kind of well sinking opening mud burst determination method. Whether the well sinking opening of pipe jacking construction will appear mud burst, mostly based on engineering experience determination, result is unreliable. The present application obtains the design parameter of well sinking opening, the specific gravity of soil body around well sinking, and the cohesion and internal friction angle of soil body;The gravity of unit width inside mud burst body, groundwater seepage force of unit width inside mud burst body, the pressure of top of unit width inside mud burst body, and the damage force when unit width inside mud burst appears are calculated;The resistance of top of unit width inside mud burst body, the resistance of bottom of unit width inside mud burst body, and the total resistance of unit width inside mud burst body are calculated;The damage force when unit width inside mud burst appears and the total resistance of unit width inside mud burst body are compared, and the determination result is obtained. The present application judges whether mud burst will appear by combining the damage force of mud burst and the resistance of mud burst, the principle is clear, the operability is strong, and more reliable result can be obtained.

This invention discloses a rock mass structural surface shear strength degradation model that simultaneously considers vibration abrasion and relative motion velocity. Addressing a significant shortcoming of current structural surface strength vibration degradation models—namely, the exaggeration of the influence coefficients of vibration abrasion and relative motion velocity on the vibration degradation of structural surface strength—this invention improves upon the aforementioned models based on the Barton criterion. It proposes a rock mass structural surface shear strength degradation model that simultaneously considers vibration abrasion and relative motion velocity. Furthermore, parameter sensitivity analysis is used to study the influence of peak ground acceleration, basic friction angle and roughness coefficient of the structural surface, and the shear strength degradation factor parameters m and P0 on slope seismic stability, providing a useful reference for slope seismic stability analysis.

The application discloses a kind of easy slip rock group fractured rock mass shear strength parameter fast estimation method, this method is first by standardized two-dimensional outcrop face conversion determination method, without equipment, quickly obtain field volume joint number J v ; further coupling J v With the rock mass strength parameter obtained by indoor rock test, the rock mass quality index BQ, the geological strength index GSI and the rock mass disturbance coefficient D are quantitatively calculated in sequence; wherein GSI is calculated by using the logarithmic closed solution formula conforming to the nonlinear evolution law of rock mass quality, and the value of D is solved by pure mathematical iteration algorithm, which completely avoids the dependence on wave velocity test equipment; finally, the improved Hoek-Brown criterion is used to complete the accurate estimation of cohesion c and internal friction angle. The application realizes the technical path innovation from equipment dependence to algorithm driving, is convenient to operate, low in cost, reliable in estimation result, and is suitable for rapid investigation and design of various easy slip fractured rock mass slopes.

The application discloses a novel method and corresponding measuring device for rapidly measuring key mechanical parameters of rock, including scratch hardness, Brinell hardness, Young's modulus and Mohr-Coulomb parameters (uniaxial compressive strength and internal friction angle). The equipment system comprises a portable frame, which contains a set of horizontal linear driving equipment, equipped with a set of linear encoders for accurately measuring horizontal displacement; the vertical direction contains a set of servo vertical driving equipment, equipped with a set of incremental magnetic encoders for accurately measuring vertical displacement, and a set of linear variable differential transformers (LVDT) for accurately sensing the slight concave-convex fluctuation of the rock surface; the servo motor drives the hemispherical composite piece through a screw rod; the size of the force in the horizontal and vertical directions of the scratch is measured by a bidirectional force sensor installed above the composite piece. The horizontal linear motor and the vertical servo motor are both loaded at a uniform speed; according to the size of the measured force, the scratch hardness and the Brinell hardness of the rock can be calculated; according to the theoretical solution of the slip line field hemispherical tooth, the Mohr-Coulomb parameters of the rock, including the uniaxial compressive strength (or cohesive force) and the internal friction angle, can be inversely calculated. When the vertical servo motor is loaded alone, the Brinell hardness of the rock can also be calculated; the Young's modulus can be calculated by the stiffness during unloading.

This invention discloses a method for determining the horizontal misalignment between segments during the construction of prefabricated caissons, comprising: obtaining the unit weight γ of each soil layer. i The thickness h of each soil layer i The internal friction angle of soil layer i on the outer sidewall of the caisson and the cohesion c of each soil layer. i ; Calculate the active earth pressure coefficient K of each soil layer based on the internal friction angle of soil layer i on the outer sidewall of the caisson. ai ; Calculate the earth pressure intensity p at the top of the upper segment above the bolt. au1 Earth pressure intensity p at the bottom of the upper segment of the bolt au2 Earth pressure intensity p of the lower segment ad Based on the earth pressure strength p of the upper segment of the bolt. au Earth pressure strength p of the lower segment ad Calculation of the height L of a single segment and the force V exerted by the bolts on the upper segment. au The force V acting on the lower segment by the bolts ad According to the force V exerted by the bolt on the upper segment au The force V acting on the lower segment by the bolts ad Calculate the uniformly distributed load q on the bolt; calculate the horizontal misalignment w between the segment rings based on the uniformly distributed load q on the bolt. This enables accurate measurement of the horizontal misalignment between the segment rings.