99 results about "Overburden" patented technology

The invention relates to the technical field of computer simulation, and discloses a computer simulation-based overlying strata multilevel grouting design optimization method, which comprises the following steps of: constructing a three-dimensional geomechanical model of a goaf according to geological exploration data; calculating development characteristics of each layer in the overlying strata of the goaf, and constructing a grouting bearing layer position of the goaf according to the development characteristics; fracture development characteristics and horizon stress distribution are analyzed; according to fracture development characteristics and horizon stress distribution, analyzing grouting simulation parameters of the horizon of the grouting bearing layer; generating a multi-level layered grouting simulation scheme of the position of the grouting bearing layer; generating a digital track of the position of a grouting bearing layer according to the multi-level layered grouting simulation scheme, and generating a grouting control simulation instruction according to the digital track; and according to the grouting control simulation instruction, multi-level grouting simulation operation is carried out on the position of the grouting bearing layer, and a multi-level grouting simulation result is output. According to the method, the accuracy of the grouting level of overlying strata multi-level design optimization can be improved.

The invention particularly discloses a rock-soil body interface torsional shear characteristic and toughness parameter unit body test device which comprises a unit body sample blank manufacturing device, a centering device, a special drilling tool, a rib body and a torque load.The rock-soil body interface torsional shear characteristic and toughness parameter unit body test device has the beneficial effects that traditional direct shear / drawing shear is replaced with torsional shear loading; the problem that the interface contact area is reduced in the shearing process is thoroughly solved, it is ensured that the interface contact area of an anchor / pile and a rock-soil body is constant, a pressure water bag is arranged at the top of a test box unit body, the original overlying and confining pressure environment of a stratum is accurately simulated, a test anchor hole / pile hole is directly manufactured through a drilling technology, and the natural roughness characteristic of the hole wall is reserved to the maximum extent; the smooth wall surface limitation of traditional mold pore forming is broken through, the basic toughness concept of the anchor / pile-rock-soil body interface is defined for the first time, the nature of the basic toughness can be quantitatively represented by the robustness of the shear resistance of the interface, a matched toughness testing technology and evaluation method are developed, and a theoretical model and a calculation tool are provided for the toughness design of anchoring engineering and pile foundation engineering.

The invention discloses a multi-dimensional comprehensive evaluation method for permeability resistance of overlying strata of a working face, and belongs to the technical field of mine engineering and geological safety evaluation. 12 types of core factors such as rock strength, rock core quality, physical and mechanical properties of rock mass, hydrological properties and mining influence characteristics are integrated; a full-process evaluation framework of data acquisition, index system construction, weight distribution, comprehensive modeling and verification optimization is constructed, an analytic hierarchy process and an entropy evaluation method are coupled to determine index weights, a dynamic evaluation model is constructed in combination with a fuzzy mathematics theory, and accurate classification and risk early warning of the permeability resistance of the overlying strata are realized. According to the method, through comprehensive analysis of a plurality of factors, the accuracy of overlying strata permeability resistance evaluation can be improved, so that the underground water permeation path and the permeation amount are predicted more accurately, the uncertainty is reduced, the comprehensiveness and the accuracy of evaluation are remarkably improved, and a scientific basis can be provided for mine water disaster prevention and control and safe mining.

The invention discloses a method and equipment for predicting surface subsidence of super-thick weakly-cemented overlying strata under insufficient mining, and belongs to the field of surface treatment of coal mining subsidence areas. Establishing a physical strata plate theoretical model according to the structure and the property of each strata, determining the size of each strata plate according to the actual mining progress of a working face, actually measured drilling data and mechanical test report parameters, and further establishing an overall model of overlying strata under the strata; the state information of each rock stratum under different advancing distances of the working face is judged, the flexural deformation value of the rock stratum in the advancing process of the working face is calculated, then the flexural value of each point of a rock stratum plate serves as the coal seam mining thickness, the subsidence deformation value of a rock-soil layer above the rock stratum subjected to flexural deformation is calculated, and then the surface subsidence value is predicted. The method has higher adaptability and accuracy for surface subsidence deformation prediction of mining areas with special stratum environments such as the condition of extremely thick and weak cemented overburden strata, calculation is simple, and a scientific theoretical basis is provided for coal mining design under regional structures.

The invention relates to the technical field of coal mining, and discloses an overlying strata multi-key layer composite pressure relief method and device, electronic equipment and a storage medium. Comprising the following steps: acquiring multi-mode rock stratum information of each overlying rock stratum of a target mining area; key strata in all the overlying strata are judged through the multi-mode strata information of all the overlying strata; based on the lithology and the mechanical property of each key layer, determining a pressure relief mode of each key layer; and determining pressure relief parameters of each key layer based on the pressure relief mode of each key layer. According to the method, the load distribution of each rock stratum is quantitatively calculated to judge the bearing capacity of each overlying rock stratum so as to preliminarily screen the key layer candidate layer, the fracture distance of the key layer candidate layer is further calculated to judge the fracture critical condition of each key layer candidate layer, and finally the key layer is screened out, so that the reliability of a key layer judgment result can be improved, and the judgment accuracy of the key layer is improved. It is ensured that the determined key layer is the optimal pressure relief layer position, and the economic benefit and efficiency of pressure relief construction can be improved.

The invention discloses a coal-pillar-free overlying strata separation layer grouting filling subsidence reduction method. The method comprises the steps that the positions of all key layers in a panel range, grouting key layers in overlying strata, the breaking distance of the grouting key layers and the mining width of a first mining face are determined; determining equivalent mining width according to the allowable mining width of a grouting key layer by utilizing the fulcrum effect of a caving zone compaction area, calculating the maximum face length of a replacement working face, and determining the length of the replacement working face within the range of the face length to obtain an overlying strata separation layer filling mining system; no coal pillar is reserved between the working faces of the overlying strata separation layer filling mining system; stoping the first mining surface, and grouting the lower part of the key layer following the stoping; when the replacement working face is mined, grouting is conducted on the lower portion of the key layer of the replacement working face; the remaining working faces are subjected to separation layer grouting and filling mining in sequence until mining of the whole panel is completed; wherein no coal pillar is reserved between all the working faces. The grouting filling subsidence reduction effect is improved, the mine coal resource recovery rate is further increased, and the mining cost is reduced.

The present invention discloses a tailings dam constructed with the aid of mining waste rock and a construction method thereof. The flood diversion dam includes a gravity dam body cast with rubble stone concrete and a back-pressure platform. The back-pressure platform is filled with mining waste rock. The back-pressure platform is constructed on the downstream side of the gravity dam body, and the back-pressure platform is arranged in contact with the inclined surface of the downstream side of the gravity dam body. The back-pressure platform spanning the entire riverbed of the present invention can significantly improve the overall stability and safety of the flood diversion dam, effectively control the uneven settlement caused by the gravity dam on the weak covering layer foundation, greatly reduce the risk of dam body cracking, and prevent the gravity dam covering layer foundation from deep shear overall instability and damage. The platform filling construction of the present invention keeps rising synchronously with the gravity dam body, and the back-pressure platform is used to build the access road to the warehouse during the construction period, which effectively solves the problem of transporting tens of thousands of cubic meters of rubble stone into the warehouse during the gradual casting and rising process of the rubble stone concrete gravity dam.

The invention relates to the technical field of deep dynamic disaster control, and discloses an overlying strata low-position pressure relief and high-position filling dynamic disaster coupling control design method which comprises the following steps: dividing strata units of a research area; and a low-position pressure relief model is established, and crustal stress balance calculation is carried out. And deep hole blasting schemes with different blasting parameters are designed, and circulating excavation and balance calculation are conducted on the coal seam till coal seam excavation is completed. Monitoring points are arranged on the overlying strata of the low-position pressure relief model, and a dynamic change curve of rock mass stress and displacement is obtained. And meanwhile, position coordinates of upper and lower rock stratum boundaries of the separation space are screened, and a grouting material unit conforming to the separation space form is generated. Proportional segmentation is carried out according to a grouting area, and different grouting filling rates are set; and designing a grouting material unit, and creating a high-position filling model. And comparing numerical results of different low-position pressure relief models and high-position filling models, carrying out coupling design on the two numerical models, and designing an optimal dynamic disaster coupling control scheme.

The invention discloses a mining area water diversion fissure zone top boundary blocking and water reducing method for preventing fissure reexpansion, which comprises the following steps: determining a grouting water interception and emission reduction treatment area of a mining area, judging the type of a water diversion fissure, and taking an upward opening fissure and a closed fissure as grouting areas; the method comprises the following steps: based on the constraint of a critical range of safe compressive strength of a consolidation body of grouting pressure and grouting liquid, on the basis of determining development characteristics of the water flowing fractures and a target grouting range, performing grouting plugging on a weathered bedrock layer where the top boundary of the water flowing fractured zone is located, by means of the method, exploring channel seam searching-filling plugging-stable water-resisting layer rebuilding is achieved, so that slurry leakage is reduced, the grouting cost is reduced, and the conditions of water guiding fracture reexpansion and loose phreatic aquifer water loss are effectively restrained; the technical problems that secondary damage is caused to overlying strata of a coal seam roof and the water plugging effect is poor due to the fact that in a crack plugging method in the prior art, the grouting pressure and the specific gravity of grout are difficult to grasp are solved.

The application discloses a kind of underground gas storage cavern depth calculation method based on expansion and crack failure in the technical field of high-pressure gas storage cavern, comprising the following steps: assuming that the failure mode of the overburden of gas storage cavern under the action of internal gas pressure is expansion and crack failure, cracks along one side of the gas storage cavern, the overburden rotates and lifts around the origin of the other side, calculates the lifting torque and anti-lifting torque with the origin, and establishes the torque balance equation, constructs the correlation calculation formula of the gas pressure in the cavern and the minimum burial depth and distance coefficient, and calculates the numerical value of the minimum burial depth of the cavern using the trial method, and the calculation accuracy meets the engineering requirements. Under the premise of ensuring the safety of the gas storage cavern, the minimum burial depth of the cavern can be accurately calculated, thereby saving investment and shortening the construction period, and the engineering benefit is remarkable.

The present application relates to a kind of subway tunnel excavation construction overburden lateral settlement prediction method, belong to subway tunnel technical field.The present application can effectively utilize the actual monitoring data in subway tunnel excavation construction, carry out the correction of Peck theory formula and the training of neural network, realize the lateral settlement prediction of overburden of mountain city subway tunnel excavation construction, provide basic data for the demarcation of subway excavation construction settlement influence range and support structure design.

The application discloses a kind of continuous monitoring methods of coal mine mining overburden rock three-dimensional interstice, belong to coal mining technical field.Through coal mine overburden rock multi-position separation layer monitoring device measurement coal seam mining after the three-dimensional interstice of overburden rock: based on coal seam mining thickness and water conducting fractured zone development height, formulate mining overburden rock interstice monitoring scheme;Perpendicular monitoring borehole is arranged on the surface above the stoping working face, and coal mine overburden rock multi-position separation layer monitoring device is installed in the borehole;Real-time acquisition, storage and analysis monitoring data are acquired by data acquisition box and computer;Based on the advancing distance of coal mining face, the evolution law of single-hole interstice of mining overburden rock is analyzed;Kriging interpolation method is used to predict the unknown point interstice of working face according to the multi-hole monitoring data, and the spatial curved surface visualization model of mining overburden rock interstice is generated.The application can realize the continuous monitoring of the distribution characteristics of overburden rock three-dimensional interstice in the process of coal seam mining, and provide a scientific basis for determining the key parameters of grouting and filling.

The invention relates to the technical field of coal mining, in particular to a thick coal seam internally-staggered roadway mining method which comprises the following steps that a first mining working face is arranged, specifically, an air return roadway of the first mining working face is located on a coal seam top plate, and the middle portion of a cutting hole of the first mining working face is located on a coal seam bottom plate; the return airway facing the first mining working face climbs at a preset gradient; the bottom coal is reserved according to the gradient set by the open-off cut of the first mining working face; a transportation roadway of the post-mining working face is located on a coal seam bottom plate and arranged below bottom coal reserved on the pre-mining working face, and the middle portion of a cut of the post-mining working face climbs towards an air return roadway of the post-mining working face at a preset gradient; according to the mining method, section coal pillars are canceled, the mining rate is increased, meanwhile, uneven sinking of overlying strata and the development height of a water guiding fracture zone are effectively controlled, and efficient and low-loss mining of the thick coal seam is achieved.

The application provides a goaf overburden strata settlement calculation method based on internal damage characteristics of overburden, and the method comprises the following steps: obtaining a detection image; determining a fractal description of a damage variable by using a digital image processing technology and a fractal box covering method according to the detection image; calculating a crack area distribution weight of overburden at different depths, and determining an optimal fractal box size according to a relationship between an information space dimension and a box covering fractal dimension; determining a fractal damage constitutive model by determining an overburden body damage factor according to the fractal description of the damage variable and the optimal fractal box size; calculating additional stress of overburden at different depths according to a stress balance principle, and calculating the settlement of overburden at different depths by using a layer summation method. By using the fractal damage constitutive relationship, the application constructs a goaf overburden strata settlement calculation model, so that the settlement of overburden at different depths is calculated, the calculation precision is improved, and the purpose of calculating the goaf overburden settlement by using the fractal theory is achieved.

The invention discloses an experimental method and device for identifying the risk of rock burst induced by dissimilatory overlying strata structure while drilling, and the method comprises the steps: constructing a geologic model of non-uniform-thickness hard overlying strata, combining a drilling device and a coal cutting device which are controlled by a computer, and simulating an underground drilling and logging process and an overlying strata response process under different mining intensities; through stress, acoustic emission, digital speckles and the like, the stope mine ground pressure and the rock burst appearing intensity are judged; through tests of different key layer thicknesses, interlayer spacing and combination forms, while-drilling multi-source information of different overlying strata structures and a large amount of data corresponding to rock burst risk grades are economically, simply and conveniently obtained; the device comprises a model frame, a loading device, a drilling device and a coal cutting device, array small holes are formed in the bottom of the model frame, and a drill rod upwards drills from the bottom of the model through the small holes. According to the method, the field actual measurement cost can be remarkably reduced, and key data are provided for establishing a risk assessment technology for identifying the dissimilatory overburden rock structure induced rock burst while drilling.

This invention relates to the field of image analysis technology, and more specifically, to a method for extracting and analyzing the dynamic range of images of damaged landforms in mining areas. The method includes: Step 1: Integrating the multispectral radiance within a set wavelength range, while subtracting two atmospheric scattering terms at each wavelength point to obtain the corrected reflectance; Step 2: Multiplying the Euclidean distance by the curvature amplitude in the near-infrared band to obtain a spectral collapse-curvature index sensitive to browning / chlorosis; Step 3: Calculating the peak elastic strain energy density per unit area of ​​overburden-coal mass; Step 4: Extracting all linear cracks from remote sensing images of the same time period and statistically analyzing their orientation histograms, then using the Shannon entropy formula to calculate the anisotropic entropy modulation of the cracks, thereby constructing a comprehensive dynamic range damage index to characterize the degree of damage to each pixel. This invention achieves accurate identification and intensity classification of surface damage areas under mining disturbance in mining areas.

The invention belongs to the technical field of goaf detection, and particularly relates to a coal mine goaf overlying strata stability monitoring device which comprises a goaf monitoring device and a bottom plate, a supporting cylinder is fixedly connected to the middle of the lower end face of the bottom plate, a conical head is fixedly connected to the lower end of the supporting cylinder, and a plurality of spring dampers are fixedly connected to the upper end face of the bottom plate. The piston end of the spring damper is fixedly connected with the bottom of the goaf monitoring device, and the goaf monitoring device is further provided with a pulley transmission type foreign matter removing mechanism for preventing foreign matter from making contact with the goaf monitoring device. By utilizing the pulley transmission type foreign matter removing mechanism and the anti-winding assembly, foreign matters on all surfaces of the goaf monitoring device can be pushed, so that the foreign matters are separated from the goaf monitoring device, and the situation that the foreign matters are in contact with the goaf monitoring device and block sensors of the goaf monitoring device is avoided; the sensor cannot accurately sense the stability change of the overlying strata, so that the accuracy of monitoring data is influenced.

The present application relates to the technical field of rainfall seepage physical simulation, and particularly relates to a rainfall seepage physical simulation experiment platform and an experiment method, comprising a base, a photogrammetry point, a Perspex baffle, a platform frame, a similar simulation coal rock stratum, a seepage monitor, a computer, a second plastic water pipe, a wastewater tank, a camera, a moisture sensor and a filter assembly, and the top outer wall of the base is fixedly connected with the platform frame; the present application is simple in experiment work, convenient in operation, high in practicability and safety, and accurate in obtained data, is suitable for a coal seam mining simulation experiment process under rainfall conditions, can obtain physical parameters such as a migration law of overburden rock, a development law of mining fissure and rainfall seepage characteristics in a coal seam mining process under rainfall seepage conditions; simulation experiment data is monitored in real time through a three-dimensional photogrammetry system and a coal rock stratum seepage monitoring system, the influence of other factors on the similar simulation experiment data is reduced, and the stability and accuracy of the data are ensured.

The application provides a kind of intelligent discrimination and enhancement method of effective barrier layer under aquifer protection in mining area, and belongs to the technical field of water-preserved mining.The method obtains geological parameters and coal rock mass physical and mechanical parameters of multiple experimental mines, uses 3DEC numerical simulation to simulate the fracture morphology of overburden rock after mining, establishes a water resource seepage model combined with COMSOL Multiphysics software, and calculates the water resource intrusion depth.Then, the relevant parameters are taken as input, the water resource intrusion depth is taken as output, the SVM model is trained to build an intelligent discrimination model of barrier layer water resource seepage, and then the water resource intrusion depth is predicted and the effective barrier layer thickness is calculated combined with the safety factor.The effective barrier layer is discriminated and processed according to different conditions.The application uses the above-mentioned intelligent discrimination and enhancement method of effective barrier layer under aquifer protection in mining area, discriminates and enhances the water-resisting capacity of the effective barrier layer, and realizes the protection of water resources in mining area.

The present invention discloses a deep overburden pile foundation concrete composite dam structure and its construction method. The pile foundation concrete composite dam structure comprises several hollow concrete dam sections, with upstream slope angles of 50° to 80° and downstream slope angles of 80° to 90°. Rubber pads are installed at the joints between the concrete dam sections and connected via dampers, which are located in the cavities of the concrete dam sections. Concrete piles and anti-seepage walls are installed in the deep overburden to support the concrete dam sections. This invention has the advantages of light weight, small cross-sectional dimensions, good economic efficiency, and low construction difficulty, making it suitable for use in conditions with restricted terrain conditions.

This application relates to the field of dam foundation seepage prevention and reinforcement construction technology, and in particular to a construction process for an ultra-deep dam foundation overburden seepage barrier wall. The process includes using a rotary drilling rig to drill along the axis of the seepage barrier wall, sequentially lowering multiple spliced ​​casings in sections, clearing the soil inside the casings, pouring concrete to form in-situ concrete piles, and before the concrete has initially set, connecting the grouting equipment and air source to the cement grout nozzle and air nozzle respectively, adjusting the casings so that the cluster injection assembly faces the adjacent pre-set piles, lifting and removing the casings in sections, and using the cluster injection assembly to directionally inject grout to form the seepage barrier wall. This application achieves the technical effect of forming a tightly overlapping seepage barrier wall in the ultra-deep dam foundation overburden layer, effectively solving the seepage problem, and being able to cope with obstacles in the strata, ensuring construction quality and effectiveness.

The invention belongs to the field of coal mine filling mining, and particularly relates to a one-side goaf overlying strata grouting filling green coal mining method which comprises the steps that a plurality of goaf grouting drill holes close to a coal wall supporting area are constructed in a mined working face; constructing a grouting filling system; injecting gangue mixed slurry into the goaf; gob-side entry driving is carried out on the reserved section coal pillar, and the width of the section coal pillar can meet the requirement that under auxiliary supporting of a goaf filling body, the section coal pillar is kept stable after working face stoping and before basic roof caving, and the section coal pillar is unstable after basic roof caving; the goaf grouting drilling holes are changed into separation layer grouting drilling holes; a plurality of separation layer grouting drill holes are constructed in the working face to be stoped; a grouting filling system is connected with the separation layer grouting drill hole; and the working face to be stoped is stoped, and grouting filling is conducted on the self-grouting drill holes. According to the method, the stress of the section coal pillar can be reduced, so that the reserved width of the section coal pillar is reduced, the coal loss is reduced, the grouting filling amount of the separation layer can be ensured, and the gangue absorption amount is ensured.

The invention relates to the technical field of compressed air energy storage, in particular to a burial depth design method and device based on a three-dimensional circular truncated cone fault optimization model and a medium, and the burial depth design method comprises the following steps: S1, determining design parameters of a gas storage; s2, substituting the design parameters into a three-dimensional rigid circular truncated cone model to calculate the burial depth H1; s3, whether the fault intersects with the overlying rock mass of the gas storage or not is judged, and if not, the burial depth H1 in the S2 serves as the safe burial depth H; if yes, the burial depth H2 is calculated by adopting a three-dimensional circular truncated cone fault optimization model; the method can make up for the blank of burial depth calculation models of unfavorable geologies such as large tank type gas storage faults and the like, and solves the problems that an existing calculation model cannot consider the influence of the faults, and the fracture surface at the fault intersection is not estimated accurately. Meanwhile, the invention provides a method for evaluating the position relation between the fault and the overlying rock mass of the gas storage and calculating the size of the fault influence area, so that the burial depth calculation result is more reasonable and reliable.

This invention relates to the field of computer simulation technology, and discloses a computer simulation-based method for optimizing multi-level grouting design in overburden. The method includes: constructing a three-dimensional geomechanical model of a goaf based on geological exploration data; calculating the development characteristics of each layer in the overburden strata of the goaf, and constructing the grouting-bearing layer based on these characteristics; analyzing fracture development characteristics and layer stress distribution; analyzing grouting simulation parameters for the grouting-bearing layer based on these characteristics; generating a multi-level layered grouting simulation scheme for the grouting-bearing layer; generating a digital trajectory of the grouting-bearing layer based on the multi-level layered grouting simulation scheme, and generating grouting control simulation commands according to the digital trajectory; performing multi-level grouting simulation operations on the grouting-bearing layer according to the grouting control simulation commands, and outputting the multi-level grouting simulation results. This invention can improve the accuracy of grouting levels in multi-level overburden design optimization.

The present invention provides a method for determining the overburden pressure of a shield tunneling tunnel, which relates to the technical field of overburden pressure determination. The method includes: obtaining a calculation theoretical model corresponding to the overburden of the shield tunneling tunnel; determining the dilatancy mobilization coefficient at different stress levels according to the calculation theoretical model; determining the included angle between the tunnel excavation shear zone and the horizontal direction corresponding to the dilatancy angle at different stress levels according to; determining the calculation formula of the overburden pressure of the tunnel with respect to the soil arch height and the calculation formula of the soil arch height with respect to the ground loss rate according to; according to the calculation formula of the overburden pressure of the tunnel with respect to the soil arch height and the calculation formula of the soil arch height with respect to the ground loss rate, determining the calculation formula of the overburden pressure of the tunnel with respect to the ground loss rate, and further determining the overburden pressure of the shield tunneling tunnel. The method in the present invention comprehensively considers various factors and can accurately determine the overburden pressure of the shield tunneling tunnel.

The invention provides a mine overlying strata structure migration comprehensive monitoring system and method, and relates to the technical field of overlying strata migration monitoring, and the method comprises the steps: a data collection module continuously collects overlying strata characteristic parameters of each region, an identification module carries out the data processing of the variable quantity of the overlying strata characteristic parameters of each region, obtains the total displacement variable quantity and the displacement direction angle, and carries out the data processing; the data processing and analysis module generates a deformation index and a deformation consistency index, the comprehensive analysis module processes all the indexes and generates a comprehensive evaluation index, and the judgment module compares the comprehensive evaluation index with a preset threshold value so as to judge the mine overlying strata risk level. According to the method, all dimensions of overlying strata deformation are comprehensively covered, and the one-sidedness problem of data acquisition is solved; dynamic tracking is realized by means of continuous multiple data acquisition, and the evaluation index is constructed to effectively make up for the deficiency of continuity and comprehensiveness of data acquisition, significantly improve the accuracy of overlying strata migration risk judgment, and realize scientific and comprehensive evaluation.

This invention provides a method for constructing sheet pile cofferdams in rocky areas with thin overburden. The method involves drilling pre-holes at designed locations on a construction platform using a pre-drilling device, followed by backfilling the boreholes with red clay. Multiple guiding mechanisms are installed inside the construction platform, and sheet piles are then driven using a pile-driving device, with the sheet piles positioned against the guiding mechanisms during driving. High-pressure jet grouting is used to seal and reinforce the sheet piles from the bottom upwards. Water is pumped out of the cofferdam, and internal supports are installed layer by layer from top to bottom. The foundation pit is excavated to the designed elevation, a cushion layer is poured, and the foundation cap is constructed. Sand is backfilled between the foundation cap and the sheet piles, and the bottom layer of internal supports is removed before constructing the pier body. The method of pre-drilling, backfilling, and high-pressure jet grouting establishes a consolidated system between the sheet piles and the rock. Backfilling sand between the foundation cap and the sheet pile cofferdam completes the first system transition. This method features a simple structure, clear stress distribution, and safe construction.

The present application relates to the field of coal underground gasification analysis, and relates to a simulation analysis method for heat transfer behavior of coal underground gasification under the condition of multiple thin coal seams. The present application divides the grid of each geological layer by the thickness of each geological layer in the target gasification coal seam and its overburden, initializes each parameter of each unit, analyzes the exothermic competition weight based on the endothermic and exothermic reaction rate of the target gasification coal seam, and further determines the net reaction heat source term, updates the temperature of the grid unit based on the net reaction heat source term of each unit, identifies the endothermic and exothermic alternating zone and locates the heat spot center in combination with the exothermic competition weight; the trajectory curvature and heat spot moving speed are obtained based on the associated heat spot center of adjacent time points, and the gasification stability is evaluated; the connected desorption domain is divided based on the overburden temperature, and the desorption window is divided according to the average temperature of the connected desorption domain at each time point, the heat action intensity index and effective desorption volume of each desorption window are calculated, and the basis for analyzing the methane thermal desorption is provided.

The invention provides a two-zone three-dimensional visualization and water disaster assessment method for weakly cemented overlying strata, and relates to the field of coal seam roof water disaster prevention and control, and the method specifically comprises the following steps: carrying out mine data collection and hydrogeological data analysis, and establishing a basic data set; coal mining overlying strata motion law analysis is carried out, and two-zone height data are obtained; establishing a coal seam roof three-dimensional hydrogeological structure model; importing the calculated'two-zone 'height data into a coal seam roof three-dimensional hydrogeological structure model, and establishing a'two-zone' three-dimensional visual hydrogeological structure model; cutting, rotating and removing the obtained'two-zone 'three-dimensional hydrogeological structure model, and performing three-dimensional visual analysis; and performing mining coal seam roof water disaster risk assessment according to the overlying strata two-zone and water-resisting layer-containing space distribution characteristics. According to the technical scheme, the problems that in the prior art, the overlying strata two-zone development height cannot be rapidly calculated, and the roof water inrush threat degree cannot be accurately evaluated are solved.

This invention relates to the field of marine engineering and structural health monitoring technology, specifically a three-dimensional identification method for overburden fissures in submarine tunnels. When there are no fissures in the propagation path between the acoustic signal transmitter and receiver, the received signal is stable; however, when fissures exist in the path, the received signal will show significant attenuation or a sharp drop. This invention achieves online, rapid, and accurate detection of overburden fissures in submarine tunnels through a multi-source spatial superposition identification algorithm based on acoustic attenuation characteristics. Utilizing the principle of multi-path superposition, it can eliminate single-path measurement errors and improve positioning accuracy. The system has a high degree of automation, can quickly acquire and process signals, and meets the online monitoring needs during construction. The equipment is flexible in installation; the transmitter only needs to be placed outside the overburden layer, reducing modifications to the internal structure of the tunnel.