43 results about "Wetting front" patented technology

The invention discloses a system for measuring soil infiltration performance and includes a constant flow water supplying device, a point source inflow device, a soil storage device and a timing device. The constant flow water supplying device is connected with a point source inflow device, used for supplying water to the point source inflow device with a constant flow and monitors the output stream; the point source inflow device is arranged on the surface of the soil stored by a soil storage device and used for leading the water flow provided by the constant flow water supplying device to enter the soil with a point source inflow mode; the soil storage device is used for storing the soil and monitoring a wetting front of the soil; a timing device is used for recording the time corresponding to the quantity of the water provided by the constant flow water supplying device and the wetting front of the soil and acquiring the soil infiltration rate of the corresponding time according to the stream flow and a wetting radius of the soil of the corresponding time, thus meeting the condition of sufficient water supplying during the test process and ensuring the undisturbed performance of the soil; thereby being able to measure the soil infiltration performance simply and accurately.

The invention discloses a method for simulating soil slope instability induced by groundwater. The method is characterized by comprising the following steps: a, putting a physical model on a centrifugal machine; b, raising the height of an external water tank, opening a water outlet valve and a water inlet valve, carrying out water seepage into a soil layer according to the thickness of a saturated soil layer and completing the saturation process of a soil mass; c, closing the water inlet valve, reducing the height of the external water tank, improving the centrifugal acceleration to solidifyand disperse the internal pore water pressure of the physical model; d, after the solidification is finished, opening the water inlet valve, raising the height of the external water tank to the corresponding height according to the preset water level height of an internal water tank; obtaining different infiltration capacity of the water to the slope when the water in the internal water tank seepsinto the soil layer and stays at different heights, and observing the wetting front change and the slope deformation condition of the physical model. The method disclosed by the invention has the advantages that the height of the groundwater level can be accurately adjusted in real time and washing of water current to the slope body is prevented; in the whole test process, high operability, highreliability and good test effect are realized.

The invention discloses a detecting device for the infiltration performance of an earth pillar. The detecting device comprises a base, a horizontal rotation adjusting mechanism, an earth pillar inlet-outlet adjusting mechanism and a height adjusting mechanism, wherein the horizontal rotation adjusting mechanism is arranged on the base; the earth pillar inlet-outlet adjusting mechanism is arranged on the horizontal rotation adjusting mechanism; the height adjusting mechanism is arranged on the earth pillar inlet-outlet adjusting mechanism. According to the invention, the device can directly detect the migration of the wetting front during the earth pillar infiltration process, and can quickly detect multiple indexes ( temperature, electric conductivity, pH and the like) during the earth pillar infiltration process, is simple in structure, can realize the detection on related indexes during the indoor earth pillar infiltration process, and can also realize the detection on related indexes during the outdoor undisturbed soil infiltration process, thereby being suitable for relevant colleges and universities as well as scientific research institutions to carry out quick detection of relevant parameters during the earth pillar infiltration process.

The invention discloses a method for calculating the debris flow channel erosion amount. The method includes the following steps that a, the flow depth hD of debris flow is obtained; b, the wetting front Zf of a ditch bed is obtained through calculation; c, the flow shear stress td of the debris flow on the surface of the ditch bed is obtained through calculation; d, the normal stress delta sigma, the tangential shear stress delta t, the normal stress sigma bot of a ditch bed matrix of the dsc position below the surface of the ditch bed and the tangential shear stress t bot are calculated; e, driving force generated after the ditch bed matrix suffers from flow of the debris flow and the dead weight static pressure and shear strength generated due to lateral horizontal stress of rock and earth mass on the two sides are calculated; f, shear strength generated by the comprehensive effect of normal stress and pore water pressure of the soil mass is calculated; g, the debris flow ditch bed is divided into multiple sections according to the gradient and the valley width, and ditch bed erosion depth is integrated along the length of the ditch bed. Physical process features such as the erosion depth can be predicted, reference is provided for design of the prevention and treatment engineering foundation embedded depth, and the method meets actual engineering requirements.

The invention relates to a soil infiltration process measuring instrument, in particular to an improved double-ring infiltration process visual test device. The device comprises an inner arc plate and an outer arc plate, a horizontal fixed plate and a vertical fixed plate which are respectively connected with the inner arc plate and the outer arc plate, a vertical connecting plate, and a transparent perforated organic glass plate. In order to observe an advancing process of a wetting front in an infiltration process of a double-ring infiltration test, the device solves the problems that a vertical moisture content distribution test has defects and the influence of preferential flow on the infiltration test is not considered. The improved double-ring infiltration process visual test device is simple in structure and low in manufacturing cost; a double-ring infiltration device is combined with the organic glass plate, so that the change of the wetting front can be observed, and the change of moisture contents of different positions can be measured.

The invention relates to an experiment instrument capable of observing the migration condition of a soil wetting front and performing layered collection on interflow. The experiment instrument comprises a soil bin, wherein a waterproof device (6) is arranged at the bottom of the soil bin. The experiment instrument is characterized in that a protecting net for preventing soil from side leakage in a rainfall process is arranged on one side surface of the soil bin; multiple interflow layered collecting devices (7) are connected with one side, located in the soil bin, of the protecting net; multiple flow guide devices (4) are connected with one side, located outside the soil bin, of the protecting net; each flow guide device (4) and the corresponding interflow layered collecting device (7) are arranged correspondingly; the other side surfaces of the soil bin are assembled by steel plates (1) and tempered glass (2). The experiment instrument can be used for collecting overland runoff, interflow at different heights of the soil layer and groundwater runoff in the rainfall process and observing movement of soil moisture through the tempered glass (2).

The invention provides an identification method for the moisture wetting front in a rock and soil medium, and a verification system thereof. The identification method comprise the following steps: calculating a value according to a formula shown in the description, wherein T is the temperature, k is the unsaturated permeability coefficient, hc is the maximum capillary rise height, hm is the matrixsuction head at a micro-control body in water-bearing rock soil, and xyz is the coordinate; and obtaining the infrared radiation thermogram of the water-bearing rock soil by using an infrared thermalimager, and regarding the position, meeting the formula, in the infrared radiation thermogram as the position of the moisture wetting front. A quantitative description equation of the infrared radiation temperature and the water content of the water-bearing rock is derived, and the identification formula of the moisture wetting front is derived based on the equation, so the method is simple, andcan be widely applied.

A method and apparatus for collection of pore water samples from a subsurface geologic formation, especially a vadose zone formation having high capillary tension. The method consists of injection of a fluid with known tracer concentrations therein into the formation. The injected displacement fluid develops a wetting front which carries with it the ambient pore water. The mixture of pore water and tracer-bearing displacement fluid is absorbed by a collection system, such as an absorbent member or pumping system. The injection and collection system are attached to a sealing borehole liner for emplacement in a borehole in the formation, and for other functions. Water samples collected in the collector system may be recovered by inversion of the liner, or alternatively by pumping. Samples thus removed from the borehole may be evaluated for chemicals, such as contaminants. The use of the tracer permits pore water characteristics to be distinguished from the motivating displacement fluid. Apparatuses for performing the foregoing functions are described.

The invention discloses a device for collecting a subsurface flow via vertical extrusion. The device comprises a sleeve and a drive rod; the drive rod is positioned in the sleeve; scales are arrangedon the outer wall of the sleeve, and the upper end of the sleeve is open while the lower end of the same is connected with a taper part; multiple radial holes are formed in different axial positions of the sleeve; a telescopic moving component is arranged in each radial hole; one side, facing the interior of the sleeve, of each telescopic moving component stretches into the sleeve and is providedwith a lower bevel; a telescopic collection cavity is arranged on one side, facing the outside of the sleeve, of each telescopic moving component; a soil moisture sensor is arranged in the telescopiccollection cavity; first push pieces of which the quantity is consistent with that of the telescopic moving components are arranged on the drive rod; the first push pieces are used for pushing the telescopic moving components outwards; an upper bevel matched with the corresponding lower bevel is arranged on the bottom surface of each first push piece. The device provided by the invention has the advantages that the soil with different depths can be collected and the water content of the soil can be analyzed, so that the migration condition of the soil wetting front and the response relation thereof to rainfall can be more objectively reflected.

The invention relates to devices for collecting interflow. The devices comprise soil bins loaded with soil, the multiple devices for collecting the interflow are inserted in the soil to collect soil moisture at different points, and the moisture of soil, which cannot be seen by naked eyes, inside the soil bins is subjected to data collecting and analyzing. The devices for collecting the interflowcan be buried in the soil, can collect the soil at different depths and can analyze the water content of the soil, and thus the transfer situation of the soil wetting front and the response relationship of the soil wetting front to rainfall are reflected more objectively.

The invention relates to a soil hydraulic property prediction method based on a cutting ring soil sample infiltration process, which adopts a brand new design method and is based on an inverse process of homogeneous dry soil one-dimensional moisture infiltration analytical solution under a constant water head boundary condition. By recording data of the accumulated infiltration amount and time in the upward infiltration process of the cutting ring soil sample and the time for a wetting front to reach the upper surface of the soil sample, the saturated hydraulic conductivity of the soil sample is measured, and the hydraulic characteristics of the soil are rapidly obtained, so that the problems of long time consumption, low efficiency, unsuitability for large-area rapid field acquisition and the like in the prior art for measuring the hydraulic characteristics of the soil are solved; the problems of multiple solutions, non-convergence and the like of parameters are avoided, the acquisition efficiency of the hydraulic characteristics of the soil is improved, and an effective means is provided for large-area investigation of the hydraulic characteristics of the soil in the field.

The invention discloses a kinetic wave infiltration method capable of describing a preferential flow phenomenon quantitatively, and belongs to the field of soil hydrology. According to the method, a soil moisture profile is divided into a preferential flow area and a matrix flow area, and an infiltration model in which the preferential flow area and the matrix flow area makes bidirectional coupling via the free water surface is provided according to a kinetic wave infiltration theory. The method can reflect wetting front change and soil moisture mutual feedback between the preferential flow and matrix flow, the problem that a present infiltration method is hard to describe the preferential flow phenomenon quantitatively is solved, and the method has high engineering significance.

The invention discloses a control method of a device for collecting the subsurface flow through vertical extrusion. The device for collecting the subsurface flow through vertical extrusion can be buried in the soil and can collect and analyze the moisture content of soil at different depths, thereby being capable of more objectively reflecting the movement of the soil wetting front and the response relation thereof to rainfall.

The invention discloses a method for estimating a two-dimensional soil moisture motion parameter under a ponding infiltration condition. The method comprises a step of estimating soil moisture motionparameters alpha, n and Ks, wherein alpha is a parameter related to air intake suction hd, n is a shape parameter, and Ks is saturated water conductivity, specifically, the estimation is performed according to a formula shown in the specification, k is a proportionality coefficient of the horizontal wetting front distance xf and the vertical wetting front distance zf; N is a shape coefficient; [theta]s is the saturated water content, [theta]r represents the retention water content, hd is the air inlet suction force, n is the shape parameter, and A3 is the power function coefficient of the fitting expression of the horizontal wetting sharp distance xf and the time t. According to the invention, the problems of complexity of a parameter estimation method, time consumption of a large number of tests and consumption of manpower and material resources in the prior art are solved.

The invention relates to the technical field of soil infiltration performance measurement, in particular to an undisturbed soil sampler and a soil infiltration performance measurement method. The undisturbed soil sampler comprises a soil sampling pipe protection sleeve, a pressure bearing cover and a soil sampling pipe; a cutting edge is arranged at the first end of the soil sampling pipe protection sleeve, and a first soil sampling pipe positioning ring surface is arranged in the soil sampling pipe protection sleeve; the pressure-bearing cover is detachably connected with the second end of the soil sampling pipe protection sleeve, and a second soil sampling pipe positioning ring surface is arranged in the pressure-bearing cover; the soil sampling pipe is used for being placed in the soilsampling pipe protective sleeve; the soil sampling pipe is made of a transparent material; a water inlet is formed in the side face of the soil sampling pipe, used for being connected with a water inlet pipe of a water supply device and provided with a sealing part. The undisturbed soil sampler can accurately collect field undisturbed soil, and the collected undisturbed soil can be directly used for undisturbed soil infiltration characteristic measurement, wetting front observation, preferential infiltration measurement and preferential flow channel observation research.

The invention discloses a device for collecting the subsurface flow through horizontal rotation and extrusion, which comprises a sleeve and a driving rod, wherein the driving rod is located in the sleeve, the outer wall of the sleeve is provided with scales, the upper end is open, the lower end is connected with a conical part, the sleeve is provided with a plurality of radial holes at different positions in the axial direction, each radial hole is internally provided with a telescopic moving component, one side of the telescopic moving component extends into the sleeve and is provided with two first guiding surfaces, the other side of the telescopic moving component is provided with a telescopic collection chamber, the telescopic collection chamber is internally provided with a soil moisture sensor, and the driving rod is provided with first pushing members with the quantity being the same as that of the telescopic moving components. The advantages lie in that the device can be buriedin the soil and can collect and analyze the moisture content of soil at different depths, thereby being capable of more objectively reflecting the movement of the soil wetting front and the responserelation thereof to rainfall.

The invention provides a method for measuring and calculating soil wetting front suction, comprising the step of establishing a quantitative relationship between the soil wetting front suction and infiltration time data characteristic parameters (the deflection, the peakedness and variation coefficient) on the basis of Philip-Dunne infiltration data analysis under the condition of three soil texture conditions of clay, loam and sandy soil. The change of water content of front and rear infiltrated soil is not need to consider and only accumulated infiltration times corresponding to different water levels in a Philip-Dunne infiltration instrument need to be observed when the method is used for measuring and calculating the soil wetting front suction, thereby simplifying the calculation process of the soil wetting front suction and improving the measuring efficiency.