141 results about "Rainfall infiltration" patented technology

The invention discloses a method for calculating the slope stability safety coefficient based on strength reduction of a humidifying condition. The method comprises the steps of testing the dry density rhod, the natural moisture content omega1, and the percentage of saturated moisture content omega2 of a slope soil body sample, testing the cohesive force c and internal friction angles of samples with different moisture contents, and calculating the volume weight gamma of the samples, wherein the formula of internal friction angles is shown in the description; drawing the relation curves of the cohesive force c and the internal friction angles respectively with the moisture content omega, and obtaining a mathematic formula of a fitting relation curve; adopting a dichotomy approximation method and considering the volume weight change, and calculating the moisture content omegaF when the slope is in critical failure; calculating the slope stability safety coefficient F. According to the method for calculating the slope stability safety coefficient based on the strength reduction of the humidifying condition, anti-shearing strength of the slope soil body is reduced based on the humidifying condition, the method better conforms to the engineering practice that the moisture content of the soil body is increased, and thus the strength is lowered due to rainfall infiltration or irrigation or the like, and the shortcoming that a prior strength reduction method is not clear in mechanical concept is overcome. When strength reduction is conducted, the adverse influence of the increase of the volume weight of the soil body on the slope stability is further considered. Therefore, the method for calculating the slope stability safety coefficient based on the strength reduction of the humidifying condition is more scientific and safer.

The invention discloses a method for planting potatoes in dry land in an all-film mulching ridging micro-furrow mode. The method includes the following steps of (1) land selection, (2) soil preparation, (3) fertilizer application, (4) ridging, (5) mulching, (6) seed preparation, (7) sowing, (8) field management, (9) disease insect and weed damage prevention, (10) harvesting and (11) waste film removing. The method has the advantages that (1) the number of rain collecting faces is increased, and the rainfall infiltration rate is increased; (2) soil moisture content on ridges and soil temperature are remarkably increased, and nutritional growth of the potatoes is promoted; (3) the soil moisture content on the ridges in rainy seasons is reduced, high-temperature high-humidity stress is relieved, and disease risks are reduced; (4) the potatoes are planted on the tops of the ridges, soil is loose, and tuber development is promoted; (5) mechanical topdressing is facilitated, and fertilizer can be directly applied to the micro ridges; (6) black mulching film is adopted to cover the whole land, and weed in the field is removed; (7) the rainfall utilization efficiency is remarkably improved, and the potato tuber yield is remarkably increased. The method has wide application prospects for potato planting in dry northwest areas.

The invention provides a multi-state undisturbed soil column infiltration simulation system and an unsaturated osmotic coefficient determination method. The simulation system comprises a bottom member, one or more soil column experiment standard members which are connected onto the bottom member and a multi-strength rainfall infiltration device arranged at the top of the soil column experiment standard members; a soil filling member of the simulation system is composed of a plurality of standard members and is automatically controlled by a computer; the determination of a rainfall infiltration coefficient and an osmotic coefficient is realized based on the system and testing steps and a calculation method are provided; in a determination process, a large-diameter undisturbed soil column is used for an indoor experiment and the multi-strength rainfall infiltration device is used for simulating three types of strength rainfall infiltration boundary conditions, such as low-strength rainfall whole infiltration boundary condition, a middle-strength rainfall radial flowing infiltration boundary condition and a high-strength rainfall stable infiltration boundary condition; and the multi-state undisturbed soil column infiltration simulation system has the characteristics of strong practicability, good utilization effect and convenience for popularization and utilization.

The invention discloses an indoor rainfall infiltration test simulation system. The indoor rainfall infiltration test simulation system comprises a support, an indoor rainfall simulation system, a soil slope seepage simulation system and a measuring system; the indoor rainfall simulation system comprises a base, a bracket and a test trough, and a soil groove, a bottom seepage collection groove, a side seepage collection groove and a runoff collection groove are formed in the test trough; the base is provided with a hinge support and a pin support, the hinge support is connected with the base in a sliding manner, the support is provided with pin holes which are sequentially distributed from bottom to top, and the hinge support is fixedly connected with the base; the test trough is fixed on the bracket, and one side, which is provided with the runoff collection groove, of the test trough is adjacent to the hinge support. By adopting the indoor rainfall infiltration test simulation system, a water transfer form and a variation rule of various physical quantities in the rainfall infiltration process in different soil textures under different slopes and different rainfall intensities can be researched.

The invention discloses a determination method for a rainstorm-induced shallow landslide disaster warning threshold value. The method comprises the steps of first, performing slope unit division basedon a DEM (Digital Elevation Model); then, establishing a stability analysis warning model based on the slope units and a critical infiltration capacity; setting five warning grades, and calculating acritical infiltration capacity threshold value of each of the five warning grades according to a meaning represented by an FS (Factor of Safety) index; and finally, establishing a landslide rainfall-infiltration model based on the slope units, calculating a relation between the infiltration capacity and a rainfall capacity of each slope unit under a specific raining condition, and reversely deducing a critical rainfall capacity of each slope unit through the critical infiltration capacity. According to the determination method for the rainstorm-induced shallow landslide disaster warning threshold value, the slope units and rainstorm influence coefficients are imported into rainstorm-induced shallow landslide mass measurement modeling, thereby improving the work efficiency of landslide warning, improving the spatial precision of landslide warning and providing basic data for researches of landslide control. The method can be applied to landslide disaster warning work in a mountainousarea and provide scientific basis for disaster prevention and reduction of the mountainous area.

The invention relates to a ridge-covering and trench-sowing cultivation and fertilization technology of dryland winter wheat, which comprises the following steps of: preparing land, applying a base fertilizer, forming ridges with the widths of 35-40cm and covering a white plastic film on the ridges; preserving a ridge width of 30-35cm between two ridges; sowing wheat in grooves with a row distance of 15-20cm and a rowing amount of 150-225 kg/ha; uncovering the film during the total growth fertility period of the wheat so as to keep the strip film covering the soil surface; ditching and topdressing a nitrogen fertilizer of 30-45 kg/hm between wheat rows when the soil starts to defrost in spring and the wheat starts to turn green; milling in time after topdressing the fertilizer; keeping the plastic film covering the ridges after wheat is harvested; and returning all straws to be covered in grooves among the ridges for stimulating the rainfall infiltration in summer and lessening the water evaporation loss of the soil. The invention can stimulate the formation and the transferring of dry substances to grains, remarkably improves the ear grain number and the thousand grain weight and remarkably increases the wheat yield.

The invention discloses a swelling soil humidifying and swelling numerical simulation method under the rainfall infiltration condition. The swelling soil humidifying and swelling numerical simulation method comprises the following steps: adopting a fluid-solid coupling module and compiling a relevant FISH language program, and realizing the relation of change of the non-saturated region matrix suction, the non-saturated permeability coefficient and the soil strength parameter along with the moisture content in the unsaturated seepage process; then based on the 'humidity stress field theory', according to the similarity of a seepage continuity differential equation and a heat conduction equation, deducing the equivalent conversion relation of a thermodynamic parameter and a seepage parameter, and adopting a thermodynamic module to realize swelling soil swelling deformation process under the humidifying condition. According to the swelling soil humidifying and swelling numerical simulation method, the swelling soil humidifying and swelling whole-process numerical calculation under the rainfall infiltration condition can be effectively and comprehensively realized, so that effective scientific guidance means are provided for engineering design and construction in the high-risk area of the swelling soil engineering disaster, and meanwhile application of the computational soil mechanics to the technical fields of practical engineering construction, geological disaster prevention and control, and the like, is powerfully driven.

The invention provides a discontinuous unsaturation soil rainfall infiltration physical simulation system and a measuring method. The discontinuous unsaturation soil rainfall infiltration physical simulation system comprises a testing soil groove, a bleed-and-feed system and a measuring system, the measuring system comprises a soil water potential measuring unit, a soil moisture measuring unit, awater head measuring unit, a soil temperature measuring unit, a soil moisture diffusion measuring unit, a data acquisition instrument and a data storage computer. According to the discontinuous unsaturation soil rainfall infiltration physical simulation system and the measuring method, a researcher can be helped to better understand related conception of unsaturated zone unsaturation seepage experiment and unsaturated zone rainfall infiltration preferential flow under the condition of understanding a discontinuous medium, permeability coefficients, soil matrix potential, soil moisture horizontal diffusion speed and the like of soil can be measured in practical application, the diffusion rate, an infiltration curve and a motion equation of unsaturation soil moisture are studied by using a measuring result, and stable data support is provided for studying the influence of soil characteristics at different collapse stages on unsaturated zone moisture displacement.

The invention relates to the technical field of shallow groundwater level fluctuation prediction and aims at conducting simulation analysis on the Lisse phenomenon considered groundwater level fluctuation situation under the rainfall condition. Therefore, according to the adopted technical scheme, the Lisse phenomenon considered shallow groundwater level prediction method comprises the following steps of 1 establishing a water-air two-phase flow model of unsaturated soil, including basic control equation and constitutive relation, and supposing that a system is always in a constant-temperature state, 2 solving the model, 3 determining the boundary conditions of the model, and 4 utilizing the water-air two-phase flow model of the unsaturated soil and using the steady seepage situation as the initial condition of rainfall infiltration to conduct simulation analysis on the Lisse phenomenon considered groundwater level fluctuation situation under the rainfall condition. The Lisse phenomenon considered shallow groundwater level prediction method is mainly applied to the shallow groundwater level fluctuation prediction.

The invention discloses a method for quickly determining the hydraulic parameters of unsaturated soil, relating to a method for testing the hydraulic parameters of unsaturated soil. The method mainly comprises the following steps of: (1) developing a multi-step flow test under a certain condition to obtain the relation curve between the saturation and the time change, simultaneously, establishing a linear viscoelastic model that accurately describes the saturation of the specimen along the time change under the condition; (2) calculating the water tolerance Ci at unit pressure and the characteristic time tci under the effect of the capillary pressure pci; and (3) calculating the saturation (Sr)eqi and the filtration coefficient ki when the specimen is in the balance state under the effect of the capillary pressure pci. The invention relates to a method for determining the hydraulic parameters of unsaturated soil based on the multi-step flow test result under a certain condition. The method is also suitable to environmental evaluation of underground pollutants, rainfall infiltration and other fields related to unsaturated soil.

The invention belongs to field of agricultural cultivation techniques, and relates to a cultivation method for crops, in particular to a furrow, film, ridge and straw combined type mulching cultivation method for the crops. The method includes the steps of farmland selection, soil preparation, ditching, ridging, basal dressing, intercropping of plants among ridge surfaces according to specification layout, ridge surface straw mulching and furrow body film mulching after crop seeding, top dressing in the seedling stage and the fast-growing stage of the plants, and recovery of mulching film after harvest. The method overcomes shortcomings of straw mulching and film mulching, achieves sustainable production of the crops, reduces waste of agricultural resources and environmental pollution, improves rainfall infiltration, restrains soil evaporation, improves hydrothermal conditions of soil, improves the nutrient status of the plants due to nutrients provided by straw, protects cultivated land, prevents loss of water and fertilizer on the surface of the soil, improves yields of the crops, changes an existing mulching cultivation production method for the crops, and achieves the purpose of protective mulching cultivation.

The invention provides a geotechnical parameter and property tester capable of simultaneously testing the specific yield and osmotic coefficient. The geotechnical parameter and property tester comprises an evaporation-preventing and gas discharge device, an experiment section, a water level observing device, a water supply device with a controllable water head, a water discharge device with a controllable water head and a water head adjusting and fixing device. The geotechnical parameter and property tester has the advantages that the tester is simple in structure, convenient to use, capable of simultaneously and accurately testing the geotechnical osmotic coefficient and specific yield and promising in application prospect; the tester is widely applicable to hydrogeology researches, and the tester can be used as a teaching instrument to help students well understand the testing principles of the specific yield and osmotic coefficient; the tester is applicable to underground water resource balance calculation, phreatic water dynamic prediction, shallow groundwater withdrawal quantity calculation, depth and interval calculation of farmland draining ditches and underground pipes, farmland irrigation and draining calculation, calculation of hydrogeological parameters such as the recharge coefficient from irrigation water infiltration and the recharge coefficient from rainfall infiltration, and various researches related to underground water.

The invention discloses a method of reinforcing and protecting a loess slope surface based on microorganism mineralization. Based on a principle that microorganisms induce a calcium carbonate precipitate, a urease-producing bacterium solution and a cementing fluid are sprayed to the loess slope surface, and urea is hydrolyzed by means of urease secreted by urease bacteria to generate carbonate ions and hydroxyl ions. Thus, in an alkaline environment, the carbonate ions are combined with calcium ions provided by calcium chloride to generate a calcium carbonate precipitate. The precipitate is mostly in a crystal state by taking the urease bacteria as a core. As the urease bacteria are attached to the surfaces of loess particles, calcium carbonate crystals and the loess particles are cementedtogether to cure loess to form a firm soil mass with certain strength and erosion resistance. By curing a soil layer of certain thickness on the surface of the loess slope surface, the shear strengthof the loess slope surface soil mass is improved, rainfall infiltration is reduced, erosion of the slope surface is prevented, the stability of a loess slope is improved, and a role of reinforcing and protecting the slope surface is played. The method is simple to construct, good in durability, environment-friendly and energy-saving and suitable for being popularized and applied.

The invention discloses a method and a device for measuring field slope surface infiltration performance and a permeability coefficient. A field slope surface double-cycle infiltrator is adopted; and the device comprises a slope infiltration ring (3), a rainfall cylinder (2) and two Marriot water tanks (1), wherein the slope infiltration ring (3) is used for being pressed into field slope surface soil and has a concentric double-ring structure; the rainfall cylinder (2) is used for allowing the rainfall capacity in an inner ring and an outer ring of the slope infiltration ring (3) to be adaptively equal to the saturated deposited water-free infiltration amount and has a concentric double-ring structure; and the two Marriot water tanks (1) are used for supplying water into the double rings of the rainfall cylinder (2). The measurement method disclosed by the invention comprises the following steps: measuring the saturated wet deposited water-free infiltration amount of the slope surface (containing the horizontal surface) and the rainfall capacity thereof, obtaining a relationship between the soil surface zero pressure saturated infiltration and the time, thereby obtaining the rainfall infiltration performance and the saturated permeability coefficient of the soil surface.

The invention relates to a multi-physical field coupling test device simulating slope instability. The device comprises a box body, an overload simulating system, a seepage simulating system, a raining simulating system, a slope inclination simulating system and a test system, wherein the top of the box body is provided with a slide way, the side of the box body is provided with a box body side plate, the overload simulating system comprises a slide block and a following loading device, the following loading device is connected to the slide block through a loading device hinge, the slide blockcooperates with the slide way and can slide on the slide way freely, and the following loading device further comprises a loading plate. Through adoption of the test device, a slope deformation instability mechanism under a condition of multi-physical field multiple physical effects of raining infiltration effect-soil unsaturation effect-underground water stable seepage effect-overload additionalstress effect-inclination stress field change effect can be discussed.

The invention relates to a regional landslide risk assessment method, system and device and a storage medium, and the method comprises the steps: obtaining regional basic data of a research region, and obtaining mechanical parameters and rainfall data according to the regional basic data; adopting a regional rainfall infiltration numerical simulation method to obtain underground water level changedata at each moment in the whole rainfall periodd according to the mechanical parameters and the rainfall data; analyzing the stability of the research area by adopting an extreme equilibrium methodto obtain a landslide occurrence probability and a landslide intensity occurrence probability at each moment in a rainfall period; and establishing a risk calculation formula of the landslide disasteraccording to all the landslide occurrence probabilities and all the landslide intensity occurrence probabilities in the rainfall period, and obtaining the risk of the research area according to the risk calculation formula. According to the method, the risk prediction model based on the rainfall-induced landslide formation mechanism is established, quantitative expression of landslide intensity in landslide risk assessment is realized, and the reliability of regional landslide disaster risk assessment is improved.

The invention discloses a permeability evaluation method of a permeable asphalt pavement based on fluid-solid coupling analysis. The method comprises the steps of determining material parameters and hydrologic parameters of structural layers of the pavement through a laboratory test, establishing unsaturated seepage models of the structural layers, establishing a numerical model of a permeable asphalt pavement system, simulating an initial moisture field in the pavement system, analyzing a rainfall infiltration process based on a saturated-unsaturated fluid-solid coupling theory, simulating adynamic variation of the moisture field under a rainfall condition, and evaluating permeability of the permeable asphalt pavement. The method comprehensively considers the influence of the initial moisture field caused by underground water and subgrade soil types in a pavement scope on the internal permeability of the pavement, and relatively accurately simulates mutual coupling and influence of the rainfall infiltration process and an underground water level fluctuation; the laboratory test and numerical simulation are combined to achieve transient analysis of the internal rainfall infiltration process of the permeable asphalt pavement system; and the method can more visually evaluate the permeability of a road structure and is practical, feasible and efficient.

The invention discloses a slope runoff-considered rainfall infiltration simulation experiment system. The experiment system includes a flow guiding tank, a water pressure tank is arranged at the upstream end of the flow guiding tank, a detection section is arranged at the middle part of the flow guiding tank, a dropper is vertically arranged at the upstream position of the detection section, a flow velocity measurement system is arranged in the detection section, a detection port is arranged at the tank bottom of the detection section, a detection container is arranged below the detection port, the inner chamber of the detection container is used for containing soil to be tested, the upper port of the detection container is in detachable abutting connection with the detection port, and thedetection container has an observation wall made of a transparent material; and the experiment system also comprises a flow velocity control system for controlling the flow velocity in the flow guiding tank and a runoff depth control structure used for controlling the runoff depth in the flow guiding tank. The experiment system can conveniently study the interference influences of soil infiltration on the above runoff and the influence rule of the change of the runoff velocity and the water depth on the soil infiltration, and has the advantages of simplicity in implementation, convenience inoperation, quickness in adjustment, and reliable structure.

The invention provides a method for simulating regional water flow movement based on coupling of soil unsaturated water and groundwater, comprising the following steps of for each finite element nodeP in the research area, adopting the following methods to obtain a grid corresponding to each finite element node P in space; calculating the rainfall infiltration of node P of finite element method;establishing a one-dimensional soil unsaturated flow simulation model; calculating the influence area AP of finite element node P; establishing a three-dimensional groundwater flow model to simulate the groundwater flow. The advantages are that (1) the spatial correlation between the remote sensing raster data and the finite element nodes is realized, which ensures the accuracy of the subsequent groundwater flow simulation by the finite element method; (2) the one-dimensional soil unsaturated flow simulation model and the three-dimensional groundwater flow model are coupled to ensure the simulation accuracy of groundwater flow.

The invention discloses an apparatus used for analyzing the seepage characteristics, deformation characteristics and stability of a coverage layer-bedrock side slope and a test method of the apparatus. The model is composed of four parts: 1) a bedrock simulative apparatus including four main parts: an upper soil baffle, an upper bedrock plate, a lower bedrock plate and a lower soil baffle, and three rotary shafts for connection, wherein the upper and the lower bed rock plates and the upper and the lower soil baffles are connected to each other through the rotary shafts; 2) a support apparatus, wherein two punched organic glass boards are arranged on two ends of a steel groove, and the three rotary shafts in the first part are inserted into the holes in the two organic glass boards for supporting the upper and the lower soil baffles and the upper and the lower bed rock plates; 3) a rainfall simulative apparatus, wherein a water feeding pipe, on which a nozzle is disposed, is fixed onto the bedrock simulative apparatus by means of a steel pipe, and a water pump supplies water to the water feeding pipe; and 4) a measuring apparatus, wherein a water content meter, a pore pressure meter and a tension meter are arranged inside the side slope, and a displacement meter is arranged on the surface of the side slope, so that seepage and displacement status of the side slope are monitored and simulated.

The invention discloses a side slope instability experiment device and method with rainfall and overload as inducements. The side slope instability experiment device is composed of a model box, a sideslope model, a rainfall simulation device, an overload simulation device, a side slope inclination device and a monitoring system. The side slope model is arranged in the model box body, and the model box body is a transparent cuboid with an upper opening. The rainfall simulation device transmits water flow to the water supply main pipe through the water inlet pipe, the water supply main pipe isconnected with the top branch pipe, and the water flow circulates in the rainfall pipe network and is sprayed to the slope model through the rainfall nozzle. The overload simulation device simulates the overload of the slope top surface through the follow-up loading device and changes the stress position of the slope top surface through the sliding block. The side slope inclination device comprises a supporting base and a jacking device. And the monitoring system obtains related data through the tester and the reading instrument and the related data is processed by the computer terminal. The experimental device can ideally simulate and monitor the deformation instability of the slope under the coupling condition of the rainfall infiltration effect and the overload additional stress effect.

The invention discloses an expansive soil side slope shallow-surface layer water control protection covering system with capillary guide and discharge grooves, and belongs to the field of geotechnical engineering and geological engineering. The expansive soil side slope shallow-surface layer water control protection covering system sequentially comprises a vegetation layer, a fine grain layer, a suction layer and a coarse grain layer from top to bottom. According to the expansive soil side slope shallow-surface layer water control protection covering system, the shallow-surface layer moisture regulation and control of the expansive soil side slope depends on a capillary blocking layer formed by combining the fine grain layer and the coarse grain layer and the capillary guide and drainage grooves which uniformly cover in the slope direction and are distributed in sections perpendicular to the slope direction. During rainfall, the shallow-surface layer moisture of the slope body is regulated and controlled in a retarding, storage and guide drainage mode, rainfall is prevented from permeating into the slope soil body, the hydrophobic capacity of a traditional capillary retarding covering layer is improved, the influence of rainfall infiltration on the slope stability is reduced, the overall stability of the slope is enhanced, and the influence of dry-wet circulation on the expansive soil slope can be reduced; and the expansive soil side slope shallow-surface layer water control protection covering system has the advantages of good protection effect, good durability, low manufacturing cost and the like.

The invention relates to a reclaimed water irrigation underground water pollution risk assessment method comprising the following steps: 1, gathering the water quality and water level of each monitoring point, and gathering positioning data and attribute data of land utilization types data; 2, building a DRASTIC model according to underground water depth, net supplement amount, aquifer medium, soil type and aeration zone medium data; scoring the underground water depth, the rainfall infiltration supplement, the aquifer medium, the soil type and the aeration zone medium influences, drafting a score graph, superposing and calculating and evaluating the underground water inherent antifouling property; 3, building a hierarchy analysis method according to the characteristic pollutant toxicity,mobility and degradability, and evaluating the underground water pollution load risks; 4, calculating the underground water values according to the aquifer characteristics, water volume, water quality, ecology and service functions; 5, calculating the reclaimed water irrigation underground water pollution risks according to the underground water inherent antifouling property, the underground waterpollution load risks, and the underground water values.

The invention discloses a device for in-situ rainfall infiltration parameter testing and a testing method. The device comprises a water supply system and an infiltration area, wherein a water supply bottom comprises a water tank and a sealed water tank arranged above the water tank; a gas inlet tube and a water outlet tube are arranged at the bottom of the sealed water tank; both the gas inlet tube and the water outlet tube extend into the water tank; a rain droplet simulation device comprises an iron wire net and a plurality of water dropping holes in the iron wire net; the bottom of the water tank is communicated with the water dropping holes through connecting water tubes. A water supply system for simulating different rainfall intensities is established, and compared with a conventional rainfall simulator, the device is very economic and practical and convenient to operate; in an effective infiltration area, a testing area soil body is isolated from a peripheral soil body by usinga grouting curtain method, water is prevented from lateral flowing in the infiltration process, interference of external environments such as evapotranspiration is also avoided, and meanwhile the timethat moisture is completely discharged from wet soil in a research area under natural conditions can be also acquired.