WO2019033467A1 - 量程可调式双环入渗装置及土壤渗透系数的原位测试方法 - Google Patents

量程可调式双环入渗装置及土壤渗透系数的原位测试方法 Download PDF

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WO2019033467A1
WO2019033467A1 PCT/CN2017/100128 CN2017100128W WO2019033467A1 WO 2019033467 A1 WO2019033467 A1 WO 2019033467A1 CN 2017100128 W CN2017100128 W CN 2017100128W WO 2019033467 A1 WO2019033467 A1 WO 2019033467A1
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bottle
ring
marsh
equivalent
markov
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PCT/CN2017/100128
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French (fr)
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刘学浩
陈征澳
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刘学浩
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
    • G01N15/08—Investigating permeability, pore-volume, or surface area of porous materials

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  • the invention belongs to the technical field of hydrogeological parameter measuring equipment, and particularly relates to an improved range-adjustable double-ring infiltration device and an in-situ testing method for soil permeability coefficient for monitoring in-situ soil infiltration coefficient/permeability coefficient.
  • the in-situ permeability coefficient test of surface soil is one of the basic physical parameters in hydrogeological survey. It is an indispensable key parameter for studying surface water-groundwater conversion, groundwater flow and solute transport.
  • the rainfall infiltration coefficient of surface soil is not only closely related to traditional farmland water conservancy problems such as soil erosion, surface runoff, farmland irrigation, water-induced geological disasters, but also hydrological process research, regional water resources assessment, hydrogeological investigation, and environmental geological prevention. Key indicators of major resource and environmental issues such as pollution performance assessment and sponge city construction are related to the development/protection of national economic development and resource environment.
  • the in-situ permeability coefficient of surface soil is a basic and important test content, involving farmland water conservancy projects, hydrogeology, engineering geology, environmental geology, sponge city construction, multi-factor comprehensive urban geology and other professional fields.
  • the in-situ test methods commonly used are: single ring infiltration, double ring infiltration, pumping test, water injection test, micro water test, tension infiltration instrument, pressure pulse method in situ tester, and the like. In-situ testing for the permeability coefficient of soil, the technique with simple test, high relative accuracy and wide application is double-ring infiltration.
  • the basic working principle of the double-ring infiltration device is: in a certain hydrogeological boundary, water is injected into the surface loose rock layer, so that the amount of water infiltrated is stable, that is, when the infiltration water volume per unit time is approximately equal, the Darcy's law is used to solve the one-dimensional stable infiltration. Permeability coefficient under conditions.
  • the composition of the double-ring infiltration equipment includes: double ring, inner Marsh bottle, outer Markov bottle, rubber tube and the like.
  • the water in the inner ring can only infiltrate vertically from top to bottom, thus eliminating the interference of lateral seepage, forming a favorable condition for one-dimensional stable vertical infiltration of the inner ring, and thus having higher than the test pit method, single ring method and the like. Precision.
  • the traditional double-ring infiltration test technology still has the following problems: 1. It is necessary to look down when observing the water level of the Markov bottle, resulting in a significant human error in the observation of the water level change; 2. The Markov bottle is measured by the water level drop. The measurement accuracy of soil infiltration is poor, there are double manual reading errors and large time accumulation errors, which seriously affect the quality of the original monitoring data. 3. For low-permeability media, the test process is carried out for a long time without interruption. The readings have caused great human and material consumption and unnecessary safety hazards in field operations. 4.
  • the main problems affecting the application of double-ring infiltration technology in the above problems are problems 1-5.
  • the technical staff has carried out unremitting research and development and improvement: for the error of the reading of the Markov bottle, the limited water supply volume, the inconvenience of carrying, etc., the constant pressure water supply is realized by the principle of the float valve or the fixed surface drainage to replace the Markov bottle.
  • the utility model patent (CN 200420008646.6) "automatic water supply double loop infiltration device", but also brings the disadvantages of complicated equipment.
  • the invention patent (CN 201510304528.2) provides an "easily installed and fixed anti-evaporation double-ring infiltration device".
  • Cao Jiansheng proposed the “automatic method for measuring rock infiltration based on the tipping method”, which is measured by replacing the Markov bottle with a tipping flowmeter.
  • the invention patent (CN 201611005336.2) provides “one”. A digital display of the Martens flask and its production method, by adding a digital vacuum gauge to the Mars flask to replace the metering.
  • the present invention combines the work needs with the prior art to provide a range-adjustable double-ring infiltration device and an in-situ test method for soil permeability coefficient, which is suitable for the in-situ high of the surface soil permeability coefficient.
  • the permeability coefficient test range can be adjusted to be more applicable, such as water conservancy projects such as irrigation and recharge of farmland, hydrogeological problems such as surface rainfall infiltration coefficient, engineering geological problems such as sponge city construction, and anti-pollution performance evaluation of surface soil layer.
  • Geological problems provide important on-site indicator parameters.
  • a range adjustable double loop infiltration device comprising at least:
  • the double ring includes an inner ring and an outer ring
  • the inner Marsh bottle communicates with an area in the inner ring
  • the outer Markov bottle communicates with an area between the inner ring and the outer ring, according to specifications It is required that the inner ring diameter is generally set to 25 cm, the outer ring diameter is 50 cm, and the height is about 50 cm, which is a conventional technique;
  • an inner Marsh bottle air outlet is disposed at an upper portion of the equivalent inner Markov bottle
  • an inner Marsh bottle water supply port and an inner Marsh bottle air inlet port are disposed at a lower portion of the equivalent inner Markov bottle.
  • the inner Marsh bottle water supply port and the inner Marsh bottle air inlet port respectively communicate with the inner ring area through a pipe, and the height of the water inlet port of the pipe connecting the inner Marsh bottle water supply port is lower than the connection.
  • the height of the inlet of the pipe of the inner Marsh bottle suction port, the end of the inner Marsh bottle suction port is set in the inner end of the equivalent inner Marsh bottle is in principle higher than the equivalent inner Markov The level of the liquid inside the bottle.
  • an outer Marsh bottle air outlet is disposed at an upper portion of the equivalent outer Markov bottle
  • an outer Marsh bottle water supply port and an outer Markov bottle air inlet port are disposed at a lower portion of the equivalent outer Markov bottle.
  • the outer Marsh bottle water supply port and the outer Marsh bottle suction port are respectively connected between the inner ring and the outer ring through a pipe
  • the height of the water inlet of the pipe connecting the water supply port of the outer Marsh bottle is lower than the height of the air inlet of the pipe connecting the suction port of the outer Marsh bottle, the suction port of the outer Markov bottle
  • the end of the pipe set inside the equivalent outer Markov bottle should in principle be higher than the liquid level inside the equivalent outer Markov bottle.
  • the integrated Martens flask further includes a piston disposed inside the integrated Martens flask and an adjustment mechanism disposed outside the integrated Martens flask.
  • the piston has the function of blocking the internal space of the integrated Martens flask, thereby forming the equivalent inner Marsh bottle and the equivalent outer Markov bottle, and the function is also that the piston has excellent fluid sealing performance guarantee.
  • the equivalent inner Markov bottle and the equivalent outer Markov bottle are separated from each other, no water force is connected and the pressure linkage effect is avoided.
  • the adjusting mechanism is connected in a spiral configuration, is disposed outside the integral Martens flask, and is connected to the internal piston, and functions to precisely control the lateral direction of the piston by the screw operation of the adjusting mechanism. Move and set the cross-sectional area of the equivalent inner Marsh bottle by setting the lateral distance scale to read the range adjustment function of the double-ring infiltration device.
  • the inner Marsh bottle air outlet is provided with a vacuum pressure sensor.
  • the adjustable double-ring infiltration device can realize the in-situ monitoring of the surface soil permeability coefficient, and the test accuracy is also greatly improved compared with the conventional technology, and is especially suitable for the case of slower infiltration and longer stable seepage time, and improves work efficiency. And the accuracy of the in-situ test data is worth promoting.
  • the invention also provides an in-situ test method for soil permeability coefficient according to the range adjustable double loop infiltration device provided by the invention, comprising at least the following steps:
  • the data acquisition card is subjected to A/D conversion, and provides a digital signal of the vacuum pressure value of the air in the Markov bottle to the computer terminal;
  • the computer terminal generates a function according to a digital signal of the vacuum pressure value of the air in the Markov bottle Calculate the soil permeability coefficient K according to the following formula:
  • a horse - is the cross-sectional area of the equivalent inner Marsh bottle, the value is adjustable, the reading is obtained in the test;
  • Ring A - is the inner ring cross-sectional area, as required by the specification is a standard circle with a diameter of 25 cm, known;
  • ⁇ g- is the density of water and the acceleration of gravity of the Earth, respectively;
  • the in-situ permeability coefficient of the surface soil is approximately equal to the infiltration coefficient of the inner ring water in the double-ring infiltration device, which can pass one.
  • the inner ring seepage volume Q is equal to the volume of the inner Marl flask, ie:
  • a horse - is the cross-sectional area of the Nei's bottle, known, the size is determined by the selected Martens flask;
  • Ring A - is the inner ring cross-sectional area, known, the size is a circular area of 25 cm in diameter;
  • ⁇ h the real-time height of the Naimer bottle liquid level, obtained by manual reading
  • Equation 5 Three important insights can be obtained from Equation 5: 1) The range of the permeability coefficient measured by the double-ring infiltration method is controlled by the cross-sectional area of the inner Markov bottle; 2) The test accuracy of the double-ring infiltration method is determined by the inner Marsh bottle surface. Height change with time (or ) Control; 3) bicyclic situ infiltration test Duration largely controlled by a set of cross-sectional area A Markov horses within the bottle, specifically described as follows:
  • test range is adjusted by the cross-sectional area of the inner Marsh bottle A horse ;
  • the traditional double-ring infiltration method uses a fixed-volume Martens flask constant pressure water supply, such as a 17cm diameter drum, the range of which is suitable for sub-sand, sub-clay with a slightly larger permeability coefficient, and is not suitable for low-permeability clay. If the cross-sectional area of the Marsh bottle of constant pressure water supply is reduced, if the diameter is reduced by 10 times to 1.7 cm, the cross-sectional area of the corresponding Nei's bottle is reduced by 100 times, and the corresponding permeability coefficient test range is expanded by 100 times. .
  • the permeability coefficient test range is linearly proportional to the cross-sectional area of the Martens flask and is proportional to the square of the diameter of the Martens flask. To a certain extent, this means that the adjustment of the permeability coefficient range has a lever amplification of four or two kilograms by adjusting the size of the Martens flask.
  • the rate of change of the liquid level of Neyma's bottle with time is to manually read the liquid level of the Nei's bottle within a certain time interval (such as 10min, 30min), and draw the infiltration velocity with time through multiple discrete data points. The curve of change.
  • a certain time interval such as 10min, 30min
  • the artificial reading of the liquid level during a fixed time interval will result in double (interval time misread, liquid level reading inaccurate), cumulative (long test time, often more than 4h, or even more than 8h) human error.
  • test time can be effectively shortened by selecting a suitable Martens flask
  • the traditional double-ring infiltration method not only has poor test accuracy, but also has great labor consumption.
  • the in-situ test of single-group double-ring infiltration test has different stabilization time for different media, such as sand for about 2h and sub-clay for about 4h, while for clay with slightly poor permeability, the stabilization time is often more than 8h.
  • the specification requires that at least 5 discrete points be required to determine whether the permeability coefficient test is stable, and it is necessary to continue to observe for more than 2 hours after stabilization. This means that a set of quality-qualified test data is completed by double-ring infiltration method as required, and the test time often exceeds 6 hours. The whole process requires technicians to work shifts, and has to pay attention to the test process without interruption for a long time.
  • the root cause of the traditional double-ring infiltration method is limited in practical applications (not suitable for low-permeability sites).
  • the artificial reading duration is too long and needs to be solved.
  • Equation 7 the magnitude of the total time t of the test is: parameter A horse (internal Markov bottle cross-sectional area) and variable h x (liquid level of the inner Markov bottle when the flow is stable), where the variable h x and The total leakage volume of the inner ring is related and thus also positively correlated with A horse . That is, the value of the total time t of the test is positively correlated with the A- horse , and reducing the cross-sectional area of the inner Marsh bottle under the same condition can greatly shorten the in-situ test time of the double-ring infiltration.
  • the in-situ test method for soil permeability coefficient aims to solve the three main problems mentioned above in the traditional double-ring infiltration method: improving test accuracy, adjusting test range, effectively shortening total test time, and conducting many attempts and innovations.
  • the specific principles are as follows:
  • an intake pipe is provided to ensure that the sum of the internal pressure of the inner Marl flask is always atmospheric pressure, that is, the lower surface water pressure P water and the upper vacuum pressure P of the Markov bottle And constant to atmospheric pressure P atm
  • Type 8 can be substituted into type 5
  • ⁇ g the density and gravity acceleration of water, respectively
  • a horse - is the cross-sectional area of the Neimar bottle, which can be obtained by reading the horizontal distance scale;
  • a ring - is the inner ring cross-sectional area, known
  • the in situ test method for soil permeability coefficient provided by the present invention is calculated based on Formula 9.
  • a vacuum pressure sensor is further provided, a vacuum pressure sensor is connected to the data acquisition card, and the data acquisition card is connected to a computer terminal equipped with data processing software, which can manually read the liquid level of the inner Marsh bottle over time. Rate of change ⁇ h/t (or ) changed to automatically measure the vacuum pressure of the inner Markov bottle as a function of time The Pt curve does not require manual reading.
  • the computer terminal automatically generates the curve of the whole process.
  • the simple linear transformation that is, multiplied by the constant ⁇ g
  • the test accuracy is greatly improved, and the total test time is due to the range. Adjustable and effective greatly shortened, the time point of the field test seepage stability is more obvious, the measurement results of the permeability coefficient value are directly output, and the whole test process is automated.
  • the permeability coefficient value can be quickly obtained by comparing the standard V-t characteristic curve and the stagnation point characteristic, and the permeability coefficient value with higher precision can be obtained even when the seepage flow is not stable.
  • the in-situ test method for soil permeability coefficient provided by the present invention can be based on two types: 1. Based on the one-dimensional stable seepage theory, and the formula 9 is substituted for the formula 5, the test accuracy and the practical effect are greatly improved; Based on the graph method, through the Vt curve of the whole process automatically outputted by the terminal, comparing the standard curve and the stagnation point feature, the permeability coefficient can be obtained quickly and accurately under the condition of unsteady flow, the total test time is further greatly reduced, and the test range is further enlarged. The scope of application has been further broadened.
  • the present invention provides a range adjustable automatic double loop infiltration device.
  • the size, material and connection method of each component can be changed according to the actual conditions on the premise of meeting the functional design requirements.
  • the adjustable range design can be applied to sandstone, sub-sand, sub-clay, clay, silt soil, bedrock weathering residual layer and other geotechnical media with different permeability coefficients.
  • the whole process is highly accurate and automatic acquisition and Vt is carried out through computer terminal.
  • the automatic monitoring design of the curve output is especially suitable for scenes with very small penetration coefficient and long test stability time.
  • the traditional internal and external Mars flasks are combined to design, which is more convenient to carry, and at the same time solve the test process. The error caused.
  • the invention provides a range-adjustable automatic double-ring infiltration device, and the internal and external Markov bottle integrated structure design is novel, and can realize automatic monitoring in the whole process, and the test precision with the permeability coefficient is greatly improved, and the test range is wider. And the three superior functions of the total test time are effectively shortened, which solves the problem that the traditional Markov bottle is inconvenient to carry out, the human reading error is large, the in-situ test manual recording takes time and labor, the in-situ test accuracy is not high, and the stable seepage at the end of the test Disadvantages such as fuzzy fuzzy conditions, can adapt to different Various sites of the order of permeability coefficient are particularly suitable for low permeability areas compared to conventional techniques. Compared with similar technology devices, it has a significant improvement in integration, automation, test accuracy, and range test time. It has good market competitiveness and industry leading advantages, and good application prospects and promotion value.
  • test range is wider, and the appropriate range is selected according to different medium adjustments.
  • range of different permeability coefficient test can be realized by adjusting the effective cross-sectional area of the inner Markov bottle, which is especially suitable for low-permeability clay which is not suitable for measurement by traditional double-ring infiltration. Muddy soil area; at the same time, the adjustable measuring range design makes the scope of application wider;
  • the test accuracy is greatly improved.
  • the internal Markov bottle surface scale (accuracy 1mm, large manual reading error and long time cumulative error) is ingeniously transformed into the Neimar bottle.
  • the change rate of the vacuum pressure value of the internal air with time increases the accuracy to 0.1% of the test accuracy of the vacuum pressure sensor, completely eliminating the error of human reading and the cumulative error of time.
  • the Vt curve of the whole process is output by the computer. Compared with the discrete points manually recorded by the traditional double-ring infiltration method, the obtained test information is more comprehensive, and the trend of the curve is more smooth and reliable. It is more convenient and quick to determine whether the seepage is stable, and the calculation of the permeability coefficient is more intuitive and accurate. ;
  • the traditional two Ma's bottles are integrated into a one-piece adjustable range Markov bottle device, which is convenient to carry out; automatic monitoring is realized in the whole process, and the required output is directly output through the computer terminal.
  • the Vt curve completely eliminates the error of human reading, greatly reduces the energy consumption of the technicians in the whole process of testing, saves labor costs, and reduces the safety risk of long-term field operations.
  • FIG. 1 is a general structural diagram of a range adjustable automatic double loop infiltration device provided by the present invention.
  • FIG. 2 is a detailed structural diagram of a range adjustable Markov bottle device in a range adjustable automatic double loop infiltration device provided by the present invention.
  • Figure 3 is a schematic view showing the structure of the adjustment mechanism portion.
  • FIG. 4 is a schematic diagram of the working principle of a range adjustable automatic double loop infiltration device provided by the present invention.
  • Figure 5 is a schematic diagram of the operation of a conventional double loop infiltration device.
  • Range adjustable Markov bottle device 1.1, integrated Martens flask, 1.2a, inner Marsh bottle outlet port 1.2b, outer Marsh bottle outlet port, 1.3, adjustment mechanism, 1.4a, inner Marsh bottle water supply Mouth, 1.4b, outer Marsh bottle water supply port, 1.5a, Neimar's bottle suction port, 1.5b, outer Marsh bottle suction port, 1.6, horizontal distance measuring ruler, 1.7, longitudinal distance measuring ruler, 1.8, Vacuum pressure sensor interface, 1.9, piston, 2a, inner Marsh bottle outlet valve, 2b, outer Marsh bottle outlet valve, 3a, inner Marsh bottle suction pipe, 3b, outer Marsh bottle suction pipe , 4a, Neim's bottle suction port regulating valve, 4b, outer Marsh bottle suction port regulating valve, 5a, Neim's bottle water supply pipe, 5b, outer Marsh bottle water supply pipe, 6, vacuum pressure sensor, 7 , data acquisition card, 8, computer terminal, 9, double ring, 10, gravel, 11, knob, 12, rotary rod, 13, thread, 14, limit ring, 15, limit sle
  • a range-adjustable automated double-ring infiltration device mainly includes a range-adjustable Martens flask device 1 and a double ring 9.
  • the range is adjustable
  • the Martens flask device 1 simultaneously serves as an inner Marsh bottle (movable rectangular piston 1.9 left space) and an outer Markov bottle (movable rectangular piston 1.9 right space) as described in the conventional art.
  • the cross-sectional area of the Nei's bottle can be adjusted, so that the double-ring infiltration device can be applied to different permeability coefficient levels (such as high permeability sand, ultra-low permeability clay, clay, silt soil, etc.) In situ test site.
  • a vacuum pressure sensor 6, a data acquisition system 7, and a computer 8 can be provided.
  • the vacuum pressure sensor 6 selects the range of 10KPa, the accuracy is 0.1%, 24V DC power supply; the data acquisition system 7 can select the NI-6008 data automatic acquisition card produced by NI Company of USA, the data acquisition frequency is set according to the in-situ test requirements.
  • the double ring 9 is a water-permeable double ring known to those skilled in the art, such as a processing size of an inner ring diameter of 25 cm, an outer ring diameter of 50 cm, and a height of 50 cm.
  • the working principle is as follows: the inner Markov bottle function carried by the left side of the adjustable range Markov bottle device is the inner ring constant pressure water supply in the double ring 9, the adjustable range Markov bottle device 1 right
  • the outer-loaded outer Marsh bottle function is the outer ring constant pressure water supply in the double ring 9, and the inner and outer liquid surfaces of the double ring 9 are always consistent due to the atmospheric pressure balance, thereby forming a one-dimensional stable infiltration condition.
  • the vacuum pressure sensor 6 connected to the upper end of the range-adjustable Martens flask device 1 reads the vacuum pressure value of the upper portion of the inner Marl flask, and the vacuum pressure value can reflect the rise and fall of the liquid surface of the inner Marsh bottle by the equivalent conversion.
  • the digital signal collected by the vacuum pressure sensor 6 is converted into a current signal by the data acquisition card 7, and converted and outputted by the computer 8, and the required value is obtained by converting the measured value of the upper vacuum pressure value of the inner ring with time (Pt).
  • the range-adjustable Martens flask device includes an integrated Martens flask 1.1, an inner Marsh flask outlet 1.2a, an external Marsh flask outlet 1.2b, an adjustment mechanism 1.3, and a Neimar bottle water supply.
  • the specific connection method is: integrated Markov bottle 1.1 rectangular frame
  • the movable rectangular piston 1.9 is partitioned into the inner Markov bottle on the left side and the outer Markov bottle on the right side, and the adjustment mechanism 1.3 can adjust the position of the movable rectangular piston 1.9 to the left and right, the precise position of which can be transversely
  • the distance measuring scale 1.6 is obtained, so the adjustability of the permeability coefficient measuring range is achieved by changing the cross-sectional area of the inner Markov bottle.
  • the upper end of the integrated Martens flask 1.1 is provided with an inner gas outlet port 1.2a and an outer Marsh bottle outlet port 1.2b for internal and external balancing of the Markov bottle.
  • the left side of the integrated Martens flask 1.1 (the inner Marsh bottle) is set to the inner Marsh bottle water supply port 1.4a and the inner Marsh bottle suction port 1.5a, and the right side (outer Marsh bottle) is set to the outer Marsh bottle water supply port.
  • 1.4b and the external Markov bottle suction port 1.5b, in the experiment can be obtained by the vertical distance measuring scale 1.7 reading to obtain the inner Marsh bottle liquid level drop value, to correct the vacuum pressure sensor converted inner ring water supply.
  • the upper left end of the integrated Martens flask 1.1 is provided with a vacuum pressure sensor interface 1.8, and is connected to the vacuum pressure sensor 6, the data acquisition system 7, and the computer 8 terminal.
  • the movable rectangular piston 1.9 is provided with an adjustment mechanism for horizontally moving the movable rectangular piston 1.9.
  • the adjustment mechanism includes a knob 11, and the knob 11 is provided with a rotary rod 12 that passes through the wall of the outer Martens flask and is movable with a rectangular shape.
  • the piston 1.9 is rotationally coupled with a thread 13 disposed in the middle of the rotary rod 12.
  • a limit ring 14 is provided at the junction of the rotary rod 12 and the rectangular piston 1.9 to limit the axial displacement of the rotary shaft 12.
  • a limit sleeve 15 is provided on the outer side of the end of the inner wall of the bottle 12 near the outer Markov bottle, and the side of the limit sleeve 15 near the thread is provided with a matching internal thread.
  • the method for measuring by the range adjustable double loop infiltration device provided by the present invention is as follows:
  • a range-adjustable automated double-ring infiltration device is designed and processed, including a range-adjustable Markov bottle device 1 and a double ring 9;
  • the aerated belt geotechnical layer of the selected pilot can represent a considerable range of surface rock and soil layers in the region.
  • the location selection of the pilot is consistent with the project objectives.
  • the depth of the buried burial of the pilot site should be greater than 5m. Otherwise, the double-ring infiltration method should be used. The error is large.
  • the test pit depth should be greater than 0.8-1.2m to eliminate the influence of factors such as surface vegetation roots and surface mixed soil in the gas-filled zone on the test;
  • the conversion coefficient of the vacuum pressure value and the water seepage flow rate is set, and the curve of the required inner ring water seepage speed with time (Vt) is obtained by the computer terminal 9 according to the curve of the upper vacuum pressure value of the inner ring with time (Pt). And output the whole process continuous water seepage speed-time curve (Vt), compared with the Vt curve manually recorded by the longitudinal distance measuring scale 1.7, when the test time (usually 30min) curve is kept in a small interval, and then continue The test can be completed in 2-3 hours;

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Abstract

一种针对原位土壤入渗系数/渗透系数实现监测的改进型量程可调式双环入渗装置及土壤渗透系数的原位测试方法, 属于水文地质参数测定设备技术领域。装置包括一体式马氏瓶(1.1)、双环(9)和调节机构(1.3)。在一体式马氏瓶(1.1)内设置有水平向移动的活塞(1.9)，活塞(1.9)将一体式马氏瓶(1.1)隔断成等效内马氏瓶(16)和等效外马氏瓶(17)；双环(9)包括内环(18)与外环(19)，等效内马氏瓶(16)连通内环(18)内的区域，外马氏瓶(17)连通内环(18)与外环(19)之间的区域。量程可调式双环入渗装置能实现地表土壤渗透系数的原位监测，测试精度较传统技术亦有大幅度提高，尤其适用于入渗较慢、稳定渗流时间较长的情况，提高了工作效率和原位测试数据精度，值得推广。

Description

量程可调式双环入渗装置及土壤渗透系数的原位测试方法 技术领域
本发明属于水文地质参数测定设备技术领域，具体涉及一种针对原位土壤入渗系数/渗透系数实现监测的改进型量程可调式双环入渗装置及土壤渗透系数的原位测试方法。
背景技术
地表土壤的原位渗透系数测试是水文地质调查中基本的物性参数之一，是研究地表水-地下水转换、地下水流动及溶质运移规律必不可少的关键参数。地表土壤的降雨入渗系数不仅与土壤侵蚀、地表产流、农田灌溉、水诱发地质灾害等传统农田水利问题密切，亦是水文过程研究、区域性水资源量评价、水文地质调查、环境地质防污性能评估、及海绵城市建设等重大资源环境问题的关键指标，关乎国民经济发展与资源环境的开发/保护。
因此，地表土壤的原位渗透系数是一项基本而重要的测试内容，涉及农田水利工程、水文地质、工程地质、环境地质、海绵城市建设、多要素综合城市地质等多个专业领域。现普遍采用的原位测试方法有：单环入渗、双环入渗、抽水试验、注水试验、微水试验、张力入渗仪、压力脉冲法原位测试仪等。针对土壤的渗透系数原位测试，测试简单、相对精度高、应用最广的技术为双环入渗。
双环入渗装置的基本工作原理为：在一定水文地质边界内，向地表松散岩层进行注水，使渗入的水量达到稳定，即单位时间的渗入水量近似相等时利用达西定律求解一维稳定入渗条件下的渗透系数。双环入渗设备组成包括：双环、内马氏瓶、外马氏瓶、橡皮管等。具体通过外环渗透场的约束作用使 内环的水只能自上而下垂直入渗，从而排除了侧向渗流的干扰，形成了内环一维稳定垂直入渗的有利条件，因此具有比试坑法、单环法等更高的精度。
但传统的双环入渗原位测试技术尚存如下诸多问题：1、观测马氏瓶水位时需要俯视，导致对水位变化的观测存在较显著的人为读数误差；2、马氏瓶通过水位下降测量土壤入渗量的测量精度较差，存在双重的人工读数误差和较大的时间累积误差，严重影响原始监测数据的质量；3、针对低渗介质时，长时间无间断地关注测试过程进行人工读数，造成了极大地人力物力的消耗及不必要的野外作业安全隐患；4、马氏瓶虽然解决了恒压入渗的问题，但外出携带不方便；5、马氏瓶供水体积有限，试验过程中马氏瓶加水会带来误差；6、一般的双环入渗装置未考虑蒸发的影响；7、仪器现场安装过程对土面的破坏引起的边界效应，使内环外环可能发生接触渗流，影响测量精度。
从可操作性和设备精度方面讲，上述问题中影响双环入渗技术应用的主要是问题1-5。对此，技术人员进行了不懈的研发与改进：针对马氏瓶读数误差、供水体积有限、携带不方便等问题，通过浮球阀或定液面排水的原理实现恒压供水，来替换马氏瓶，如实用新型专利(CN 200420008646.6)“自动供水双环入渗装置”，但也带来设备过复杂的缺点。针对蒸发影响及内环外环安装对土面破坏的问题，发明专利(CN 201510304528.2)提供一种“易于安装和固定的防蒸发型双环入渗装置”。针对马氏瓶测量精度低的问题，曹建生提出了“基于翻斗法量水的岩土入渗自动测定方法”通过翻斗式流量计替代马氏瓶来计量，发明专利(CN 201611005336.2)提供“一种数显马氏瓶及制作方法”，通过马氏瓶加设数显真空计来替代计量。
上述诸多改进仅部分解决了如前所述的技术问题，一定程度提高了双环入渗装置的适用性、可操作性和测量精度，但仍然没能实现原位测试精度实质性的提升(问题1-2)，原位测试仍然没能实现全程自动化(问题3)，测 试手段仍显耗时耗力(问题3-5)。
发明内容
为解决现有技术的不足，本发明结合工作需要和已有技术积累，提供了一种量程可调式双环入渗装置及土壤渗透系数的原位测试方法，适用于表层土壤渗透系数的原位高精度测试，渗透系数测试量程可调节从而适用性更广，为农田灌溉补给等水利工程、地表降雨入渗系数等水文地质问题、海绵城市建设等工程地质问题、地表土层防污性能评价等环境地质问题提供重要的现场指标参数。
本发明所提供的技术方案如下：
一种量程可调式双环入渗装置，至少包括：
一体式马氏瓶，在所述一体式马氏瓶内设置有水平向移动的活塞，所述活塞将所述一体式马氏瓶隔断成等效内马氏瓶和等效外马氏瓶；
双环，所述双环包括内环与外环，所述内马氏瓶连通所述内环内的区域，所述外马氏瓶连通所述内环与所述外环之间的区域，按规范要求，内环直径一般设置为25cm，外环直径为50cm，高约50cm，为常规技术；
具体的，在所述等效内马氏瓶的上部设置有内马氏瓶出气口，在所述等效内马氏瓶的下部设置有内马氏瓶供水口和内马氏瓶吸气口，所述内马氏瓶供水口和所述内马氏瓶吸气口分别通过管道连通所述内环内的区域，连通所述内马氏瓶供水口的管道的进水口的高度低于连通所述内马氏瓶吸气口的管道的进气口的高度，所述内马氏瓶吸气口的管道设置在等效内马氏瓶内部的一端原则上应高于等效内马氏瓶内部的液面高度。
具体的，在所述等效外马氏瓶的上部设置有外马氏瓶出气口，在所述等效外马氏瓶的下部设置有外马氏瓶供水口和外马氏瓶吸气口，所述外马氏瓶供水口和所述外马氏瓶吸气口分别通过管道连通所述内环与所述外环之间 的区域，连通所述外马氏瓶供水口的管道的进水口的高度低于连通所述外马氏瓶吸气口的管道的进气口的高度，所述外马氏瓶吸气口的管道设置在等效外马氏瓶内部的一端原则上应高于等效外马氏瓶内部的液面高度。
具体的，所述的一体式马氏瓶，还包括设置在一体式马氏瓶内部的活塞和设置于一体化马氏瓶外部的调节机构。所述的活塞，其功能在于，隔断一体化马氏瓶的内部空间，进而形成所述的等效内马氏瓶和等效外马氏瓶，其功能还在于，活塞优异的流体密封性能保证了等效内马氏瓶和等效外马氏瓶相互隔断，无水力联系且避免了压力联动效应。所述的调节机构，其连接方式在于，以螺旋构型设计，设置在一体式马氏瓶外部，与内部的活塞连接，其功能在于，通过所述的调节机构的螺旋操作精确控制活塞的横向移动，并通过设置的横向测距标尺读数得到等效内马氏瓶的横截面积，从而实现双环入渗装置的量程调节功能。
进一步的，所述内马氏瓶出气口设置有真空压力传感器。
该量程可调式双环入渗装置能实现地表土壤渗透系数的原位监测，测试精度较传统技术亦有大幅度提高，尤其适用于入渗较慢、稳定渗流时间较长的情况，提高了工作效率和原位测试数据精度，值得推广。
本发明还提供了根据本发明所提供的量程可调式双环入渗装置进行的土壤渗透系数的原位测试方法，至少包括以下步骤：
1)通过调节所述调节机构来移动所述活塞，以调整所述内马氏瓶横截面积A马；
2)以所述量程可调式双环入渗装置进行土壤渗透系数的原位测试，所述真空压力传感器向所述数据采集卡输入所述内马氏瓶中空气的真空压力值的模拟信号；
3)所述数据采集卡经过A/D转换，向所述电脑终端提供马氏瓶中空气的真空压力值的数字信号；
4)所述电脑终端根据所述马氏瓶中空气的真空压力值的数字信号生成函数
Figure PCTCN2017100128-appb-000001
并根据下述公式计算土壤渗透系数K：
Figure PCTCN2017100128-appb-000002
其中，A马-为等效内马氏瓶的横截面积，数值可调，试验中读数得到；
A环-为内环横截面积，如规范要求为直径25cm的标准圆形，已知；
ρg-分别为水的密度和地球的重力加速度，已知；
Figure PCTCN2017100128-appb-000003
-指等效内马氏瓶内压力值随时间变化的微分函数，试验中由电脑终端生成；
上述测试方法的原理如下：
传统方法中，当渗水试验延续时间较长，渗透速度随时间的曲线趋于稳定时，地表土壤的原位渗透系数数值上近似等于双环入渗装置中内环水的入渗系数，可通过一维稳定渗流条件下的达西公式求解：
K≈v              [1]
Figure PCTCN2017100128-appb-000004
忽略蒸发作用的影响下，内环渗水体积Q等于内马氏瓶补给的体积，即：
渗水体积：Q＝A马·Δh                     [3]
渗透系数：
Figure PCTCN2017100128-appb-000005
联立公式1、2、3、4可得，渗透系数：
Figure PCTCN2017100128-appb-000006
微分形式表达：
Figure PCTCN2017100128-appb-000007
式中：
Q—为内环渗水体积，为随时间变化的变量；
K—为渗透系数，
v—为内环入渗速度。
A马-为内马氏瓶的横截面积，已知，大小由选择的马氏瓶确定；
A环-为内环横截面积，已知，大小为规范规定直径25cm的圆形面积；
t—为入渗时间，通过计时器人工读数得到；
Δh—内马氏瓶液面实时高度，通过人工读数得到；
由式5可得3条重要认识：1)双环入渗法测渗透系数的量程由内马氏瓶的横截面积A马控制；2)双环入渗法的测试精度由内马氏瓶液面高度随时间变化率
Figure PCTCN2017100128-appb-000008
(或
Figure PCTCN2017100128-appb-000009
)控制；3)双环入渗法原位测试一组的全程时间很大程度上由内马氏瓶的横截面积A马控制，具体阐述如下：
1)测试量程由内马氏瓶的横截面积A马调节；
传统的双环入渗方法采用固定体积的马氏瓶恒压供水，如直径为17cm的圆桶，其量程适用于渗透系数稍大的亚砂土、亚粘土，不适合低渗的粘土。若将恒压供水的马氏瓶横截面积缩小，如直径缩小10倍变为1.7cm，对应的内马氏瓶横截面积缩小100倍，其对应的渗透系数测试量程相应地了扩大100倍。由此可见，渗透系数测试量程线性正比于马氏瓶横截面积，正比于马氏瓶直径的平方。这一定程度上意味着，通过马氏瓶大小的调节变化，对渗透系数量程的调节具有四两拨千斤的杠杆放大作用。
2)测试精度由内马氏瓶液面高度随时间变化率
Figure PCTCN2017100128-appb-000010
控制；
内马氏瓶液面高度随时间的变化率，传统方法为一定时间间隔内(如10min、30min)人工读取内马氏瓶的液面高度，通过多个离散数据点绘制入渗速度随时间变化的曲线。然而，固定时间间隔内人工读取液面高度会产生双重的(间隔时间读不准、液面高度读不准)、累积的(试验时间长，常常超过4h，甚至8h以上)人为读数误差。
此外，原位测试时判断渗流是否稳定的时间点存在困难，通过人工读数的离散点数据计算最终稳定的渗透系数值存在不可回避的数据处理误差。
3)测试时间可通过选择合适的马氏瓶而有效缩短；
传统的双环入渗方法不仅测试精度差，而且存在极大的人力消耗。单组双环入渗原位测试实验针对不同的介质其稳定时间不同，如砂土约2h，亚粘土约4h，而针对渗透系数稍差的粘土，其稳定时间往往超过8h。规范要求判定渗透系数测试是否稳定至少需5个离散点，且稳定后还需持续观察2h以上。这意味着，按要求采用双环入渗法完成一组质量合格的测试数据，测试时间往往超过6h，且测试全过程需要技术人员轮班值守，不得不长时间无间断地关注测试过程，适时进行人工读数，由此造成了极大的人力物力消耗及不必要的安全隐患。值得进一步注意的是，在野外原位测试时技术人员出于可操作性和野外作业安全的角度考虑，整个测试过程超过10h，或马氏瓶2个离散数据点之间的等待时间超过1h时，即认为该处不适宜采用双环入渗法。
综上所述，除测量精度不高外，造成传统双环入渗方法在实际应用中受限(不适宜低渗场地)的根本原因是人工读数持续时间过长，亟待解决。
由式5可得，
Figure PCTCN2017100128-appb-000011
对微分式6进行积分变换，测试的总时间为：
Figure PCTCN2017100128-appb-000012
由式7可知，影响测试总时间t数值大小的分别为：参数A马(内马氏瓶截面积)和变量hx(渗流稳定时内马氏瓶的液面高度)，其中变量hx与内环总渗漏体积相关，因而亦与A马呈正相关。即测试总时间t的数值大小与A马呈指数级正相关，在同一条件下减小内马氏瓶横截面积，可大大缩短双环入渗的原位测试时间。
本发明所提供土壤渗透系数的原位测试方法为针对性解决传统双环入渗方法上述的三个主要问题：提高测试精度、测试量程可调节、有效缩短总测试时间，进行了诸多尝试与革新，其具体原理阐述如下：
考虑到内马氏瓶给内环恒压供水时，设置有进气管，保证了内马氏瓶内部压力之和始终为大气压，即马氏瓶下部液面水压力P水与上部真空压力P之和恒定为大气压Patm
Patm＝P水+P真＝ρgΔh+P           [8]
式8代入式5可
Figure PCTCN2017100128-appb-000013
式中：
ρg—分别为水的密度和重力加速度，常数；
A马-为内马氏瓶的横截面积，通过横向测距标尺读数可求得；
A环-为内环横截面积，已知；
p—为内马氏瓶的真空压力值，读数可得；
Figure PCTCN2017100128-appb-000014
—为内马氏瓶中空气的压力值随时间的变化率，通过数据或曲线输出可得；
本发明所提供的土壤渗透系数的原位测试方法，基于式9计算得到。
为提高测量精度、减小人力消耗，进一步设置真空压力传感器，真空压力传感器接数据采集卡，数据采集卡接搭载有数据处理软件的电脑终端，可将人工读取内马氏瓶液面随时间的变化率Δh/t(或
Figure PCTCN2017100128-appb-000015
)转变为自动测量内马氏瓶真空压力随时间变化
Figure PCTCN2017100128-appb-000016
的P-t曲线，不需要人工读数，电脑终端自动生成全过程的曲线，简单的线性转化(即乘以常数ρg)即可得到测试全过程的V-t曲线，测试精度大幅度提高，测试总时间因为量程可调而有效地大大缩短，野外测试渗流稳定的时间点判定更明显，测量结果渗透系数值直接输出，整个测试过程实现了自动化。
除上述采用一维稳定渗流理论计算近似的入渗速度方法以外，还可以采用图表法。
Figure PCTCN2017100128-appb-000017
而通过本发明提供的自动化全过程V-t曲线，对比标准的V-t特征曲线及驻点特征，可快速得到渗透系数值，甚至在渗流尚未稳定时即可得到精度较高的渗透系数值。
也就是说，本发明所提供的土壤渗透系数的原位测试方法可基于两种：1、基于一维稳定渗流理论，以式9代替式5，测试精度和实用效果有较大程度改进；2、基于图表法，通过终端自动输出的全过程V-t曲线，对比标准曲线及驻点特征，可在非稳定流条件下快速精准地得到渗透系数，测试总时间进一步大大缩小，测试量程进一步变大，适用范围进一步变广。
总体上，本发明所提供的一种量程可调式自动化双环入渗装置。各元件尺寸、材质、连接方式可在满足功能设计要求的前提下依实际情况变更选择。量程可调的设计能适用渗透系数不同数量级的砂土、亚砂土、亚粘土、粘土、淤泥质土、基岩风化残积层等岩土介质；全过程高精度自动化采集并通过电脑终端进行V-t曲线输出的自动化监测设计，尤其适用于渗透系数极小、测试稳定时间较长的场景；将传统的内外马氏瓶合并设计，携带更方便，同时一定程度解决了测试过程马氏瓶中途换水引起的误差。适用于区域性水利工程、水文地质、工程地质、环境地质调查，如海绵城市、市政工程、水利工程涉及的渗漏量计算，小流域降雨入渗系数计算，暴雨等极端气候条件下工程场地的力学稳定性评估，污染场地入渗系数评价与防污性能评估，等等。
本发明与现有技术相比，其有益效果和优点在于：
本发明所提供的一种量程可调式自动化双环入渗装置，内外马氏瓶一体化的结构设计较新颖，能实现全过程自动监测，兼具渗透系数的测试精度大幅度提高、测试量程更广和测试总时间有效缩短的3大优越功能，解决了传统的马氏瓶外出携带不便、人为读数误差大、原位测试人工记录耗时耗力、原位测试精度不高及试验结束时稳定渗流条件判定模糊等缺点，能适应不同 渗透系数量级的各种场地，相比于传统技术尤其适合低渗地区。较同类技术装置在集成化、自动化、测试精度、量程范围测试时间等方面有较大幅度提升，具有较好的市场竞争力和业内领先优势，及良好的应用前景和推广价值。
1)测试量程更广，依据不同介质调节选取合适的量程。在严密的理论公式推导下，指出通过调节内马氏瓶的有效横截面积来实现双环入渗法不同渗透系数测试的量程可选，尤其适用于传统双环入渗不适宜测量的低渗粘土、淤泥质土区域；同时，测试量程可调的结构设计使得其适用范围进一步变广；
2)测试精度大幅提高，从传统方法的人为读取内马氏瓶液面刻度(精度1mm，有较大的人工读数误差及长时间累积误差)随时间的变化率巧妙转化为内马氏瓶内空气的真空压力值随时间的变化率，精度提升至真空压力传感器的测试精度0.1％，彻底消除了人为读数误差和时间累积误差。电脑输出全过程V-t曲线，较传统双环入渗法人工记录的离散点，得到的测试信息更全面、呈现的曲线变化趋势更平滑可靠；判定渗流是否稳定更方便快捷，计算渗透系数值更直观准确；
3)测试总时间呈指数级缩短，有效降低了人力投入。通过严密的理论公式推导指出双环入渗原位测试总时间
Figure PCTCN2017100128-appb-000018
其数值大小与内马氏瓶横截面积呈指数级正相关，通过调节等效内马氏瓶的有效横截面积来缩短测试总时间；
4)集成化、自动化程度高，将传统的2个马氏瓶集成设置为1体化的量程可调式马氏瓶装置，外出携带方便；全过程实现自动化监测，通过电脑终端直接输出所需的V-t曲线，彻底消除了人为读数误差，大幅度减轻了测试全过程中技术人员持续记录的精力消耗，节省了人力成本，减小了长时间野外作业安全风险。
附图说明
图1是本发明所提供的一种量程可调式自动化双环入渗装置的总体结构图。
图2是本发明所提供的一种量程可调式自动化双环入渗装置中量程可调式马氏瓶装置的细节结构图。
图3是调节机构部分的结构示意图。
图4是本发明所提供的一种量程可调式自动化双环入渗装置工作原理图。
图5是传统双环入渗装置的工作原理图。
附图1、2、3中，各标号所代表的部件列表如下：
1、量程可调式马氏瓶装置，1.1、一体化马氏瓶，1.2a、内马氏瓶出气口1.2b、外马氏瓶出气口，1.3、调节机构，1.4a、内马氏瓶供水口，1.4b、外马氏瓶供水口，1.5a、内马氏瓶吸气口，1.5b、外马氏瓶吸气口，1.6、横向测距标尺，1.7、纵向测距标尺，1.8、真空压力传感器接口，1.9、活塞，2a、内马氏瓶出气口调节阀，2b、外马氏瓶出气口调节阀，3a、内马氏瓶吸气管，3b、外马氏瓶吸气管，4a、内马氏瓶吸气口调节阀，4b、外马氏瓶吸气口调节阀，5a、内马氏瓶供水管，5b、外马氏瓶供水管，6、真空压力传感器，7、数据采集卡，8、电脑终端，9、双环，10、砾石，11、旋柄，12、旋杆，13、螺纹，14、限位环，15、限位套管，16、等效内马氏瓶，17、等效外马氏瓶，18、内环，19、外环。
具体实施方式
以下对本发明的原理和特征进行描述，所举实施例只用于解释本发明，并非用于限定本发明的范围。
在一个具体实施方式中，如图1所示，一种量程可调式自动化双环入渗装置，主要包括量程可调式马氏瓶装置1和双环9。如图1所示，量程可调 式马氏瓶装置1同时充当传统技术所述的内马氏瓶(可移动式的矩形的活塞1.9左侧空间)和外马氏瓶(可移动式的矩形的活塞1.9右侧空间)，此外，内马氏瓶的横截面积可调节，从而使该双环入渗装置可适用于不同渗透系数量级(如高渗透率的沙土、超低渗的亚粘土、粘土、淤泥质土等)的原位测试现场。
进一步，可设置真空压力传感器6、数据采集系统7和电脑8。
其中，真空压力传感器6选型量程10KPa，精度0.1％，24V直流电供电；数据采集系统7可选美国NI公司生产的NI-6008型数据自动采集卡，数据采集频率依原位测试要求设定，如1次/min；双环9为本领域人员公知的渗水双环，如加工尺寸为内环直径25cm，外环直径50cm，高50cm。
如图4、5所示，其工作原理在于：量程可调式马氏瓶装置1左侧承载的内马氏瓶功能为双环9中的内环恒压供水、量程可调式马氏瓶装置1右侧承载的外马氏瓶功能为双环9中的外环恒压供水，双环9的内外液面因大气压平衡而始终保持一致，由此形成了一维稳定入渗条件。其中，通过量程可调式马氏瓶装置1上端连接的真空压力传感器6读取内马氏瓶上部的真空压力值，该真空压力值可通过换算等效反映内马氏瓶液面的升降。故通过数据采集卡7将真空压力传感器6采集的数字信号转换为电流信号，并通过电脑8进行换算输出，通过实测的内环上部真空压力值随时间的变化曲线(P-t)换算得到所需的内环渗水速度随时间变化的曲线(V-t)，从而得到一维稳定入渗条件下的原位渗透系数值。
量程可调式马氏瓶装置1，如图2所示，包括一体化马氏瓶1.1，内马氏瓶出气口1.2a、外马氏瓶出气口1.2b、调节机构1.3、内马氏瓶供水口1.4a、外马氏瓶供水口1.4b、内马氏瓶吸气口1.5a、外马氏瓶吸气口1.5b、横向测距标尺1.6、纵向测距标尺1.7、真空压力传感器接口1.8、可移动式的矩形的活塞1.9。如图2所示，其具体连接方式在于：一体化马氏瓶1.1矩形框架 通过可移动式的矩形的活塞1.9隔断为左侧的内马氏瓶和右侧的外马氏瓶，调节机构1.3可左右调节可移动式的矩形的活塞1.9的位置，其精确位置可通过横向测距标尺1.6读数得到，故通过改变内马氏瓶的横截面积实现渗透系数测量量程的可调节性。一体化马氏瓶1.1上端开孔设置内马氏瓶出气口1.2a和外马氏瓶出气口1.2b，用于马氏瓶加水时内外平衡。一体化马氏瓶1.1的左侧(内马氏瓶)设置内马氏瓶供水口1.4a和内马氏瓶吸气口1.5a，右侧(外马氏瓶)设置外马氏瓶供水口1.4b和外马氏瓶吸气口1.5b，实验中可通过纵向测距标尺1.7读数得到内马氏瓶液面下降值，校正真空压力传感器换算的内环供水量。一体化马氏瓶1.1左侧上端设置真空压力传感器接口1.8，并连接真空压力传感器6、数据采集系统7和电脑8终端。可移动式的矩形的活塞1.9设置有调节机构，用于水平移动可移动式的矩形的活塞1.9。在一个具体的实施方式中，如图3所示，调节机构包括旋柄11，旋柄11设置有旋杆12，旋杆12穿过外马氏瓶的瓶壁并与可移动式的矩形的活塞1.9转动连接，在旋杆12的中间设置有螺纹13。在旋杆12与矩形活塞1.9的连接处设置有限位环14，限制旋杆12的轴向位移。在旋杆12靠近外马氏瓶的瓶内壁的一端的外侧设置有限位套管15，限位套管15靠近螺纹的一侧设置有匹配的内螺纹。
以本发明所提供的量程可调式双环入渗装置进行测量的方法如下：
1)按照本发明设计加工一种量程可调式自动化双环入渗装置，包括量程可调式马氏瓶装置1和双环9；
2)确定试点，开挖试坑。所选试点的包气带岩土层能代表该区域相当大范围的地表岩土层情况，试点的位置选择与工程目标一致，试点场地的潜水埋藏深度宜大于5m，否则采用双环入渗法测试误差较大。试坑深度应大于0.8-1.2m，以消除包气带表层植被根系、表层杂填土等因素对试验的影响；
3)压入双环、铺砾、立标。将双环9同心压入试坑底部中央，原则上 压入0.8-1cm即可，为切断内外环水力联系，压入深度的实际控制范围为3-8cm。进而，对内外环底部铺砾，厚约3-4cm，目的在于防止注水时将环底的沙土层冲起。定水头注入时，为控制环底水层厚度，需进行立标，一般“水层厚度”控制在10cm左右；
4)定水头注水、观测。以环底水标为准，保持标头刚好淹在水中，内外环同时定水头注水，使双环9的内外水柱始终保持在10cm的同一高度。这样内外环之间渗入的水主要消耗在侧向扩散上，内环渗入的水主要消耗在垂向渗透上，保证了形成稳定一维垂向渗流的条件；
5)调节内马氏瓶横截面积，选择合适的渗透系数测量量程。通过调节机构1.3左右调节可移动式的矩形的活塞1.9的位置，选择该场地岩土层类型对应的横向测距标尺1.6刻度，目的在于有效缩短测试时间，选择合适的量程范围提高监测精度。选定后开始观测，通过记录纵向测距标尺1.7显示的内马氏瓶液面高度和时间，绘制出渗水速度时间曲线(V-t)，此为传统的双环入渗人工记录法；
另，设定真空压力值与渗水流量的换算系数，通过电脑终端9根据内环上部真空压力值随时间的变化曲线(P-t)换算得到所需的内环渗水速度随时间变化的曲线(V-t)，并输出全过程连续的渗水速度-时间曲线(V-t)，与通过纵向测距标尺1.7人工记录的V-t曲线对比标定，当试验时间(一般为30min)曲线保持在一个不大的区间，再延续2-3小时即可结束试验；
6)人工记录法连续观测(20min时间间隔)两次数据之差不大于5％，或电脑输出的V-t曲线渐趋稳定，无明显下降或浮动趋势，即可结束试验。其中电脑输出V-t曲线的渐进值即为所求的渗透系数值；
7)渗透系数原位测试结束，关闭各阀门，保持安置状态至下一个试点。标定完成后可直接读取电脑输出的V-t曲线，测试过程无需人工记录。
以上所述仅为本发明的较佳实施例，并不用以限制本发明。本发明中， 为了方便阐述，材料、尺寸、数量等的变化不超过本发明的表述范围。凡在本发明的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本发明的保护范围之内。

Claims (7)

  1. 一种量程可调式双环入渗装置，其特征在于，至少包括：
    一体式马氏瓶(1.1)，在所述一体式马氏瓶(1.1)内设置有活塞(1.9)，所述活塞(1.9)将所述一体式马氏瓶(1.1)隔断成等效内马氏瓶和等效外马氏瓶；
    双环(9)，所述双环(9)包括内环(18)与外环(19)，所述内马氏瓶连通所述内环(18)内的区域，所述外马氏瓶连通所述内环(18)与所述外环(19)之间的区域；
    以及调节机构(1.3)，所述调节机构(1.3)可控制所述活塞(1.9)移动以调整所述等效内马氏瓶和所述等效外马氏瓶的横截面积。
  2. 根据权利要求1所述的量程可调式双环入渗装置，其特征在：在所述等效内马氏瓶的上部设置有内马氏瓶出气口(1.2a)，在所述等效内马氏瓶的下部设置有内马氏瓶供水口(1.4a)和内马氏瓶吸气口(1.5a)，所述内马氏瓶供水口(1.4a)和所述内马氏瓶吸气口(1.5a)分别通过管道连通所述内环(18)内的区域，连通所述内马氏瓶供水口(1.4a)的管道的进水口的高度低于连通所述内马氏瓶吸气口(1.5a)的管道的进气口的高度。
  3. 根据权利要求1所述的量程可调式双环入渗装置，其特征在于：在所述等效外马氏瓶的上部设置有外马氏瓶出气口(1.2b)，在所述等效外马氏瓶的下部设置有外马氏瓶供水口(1.4b)和外马氏瓶吸气口(1.5b)，所述外马氏瓶供水口(1.4b)和所述外马氏瓶吸气口(1.5b)分别通过管道连通所述内环(18)与所述外环(19)之间的区域，连通所述外马氏瓶供水口(1.4b)的管道的进水口的高度低于连通所述外马氏瓶吸气口(1.5b)的管道的进气口的高度。
  4. 根据权利要求1至3任一所述的量程可调式双环入渗装置，其特征在： 所述内马氏瓶出气口(1.2a)设置有真空压力传感器(6)，所述真空压力传感器(6)连接数据采集卡(7)，所述数据采集卡(7)电连接电脑终端(8)。
  5. 一种根据权利要求4所述的量程可调式双环入渗装置进行的土壤渗透系数的原位测试方法，其特征在于，至少包括以下步骤：
    1)利用所述调节机构(1.3)来移动所述活塞(1.9)，以调整所述等效内马氏瓶横截面积；
    2)利用所述量程可调式双环入渗装置进行土壤渗透系数的原位测试，所述真空压力传感器(6)向所述数据采集卡(7)输入所述等效内马氏瓶中空气的真空压力值的模拟信号；
    3)所述数据采集卡经过A/D转换，向所述电脑终端(8)提供所述等效马氏瓶中空气的真空压力值的数字信号；
    4)所述电脑终端(8)根据所述等效马氏瓶中空气的真空压力值的数字信号生成P-t曲线，再转化为V-t曲线，对V取渐进值Vk，得到土壤渗透系数K。
  6. 根据权利要求5所述的量程可调式双环入渗装置进行的土壤渗透系数的原位测试方法，其特征在于，步骤4)中，在一维稳定渗流条件下：
    Vk≈K
    Figure PCTCN2017100128-appb-100001
    其中，A马为等效内马氏瓶的横截面积，A环为内环(18)横截面积，ρ为水的密度，g为地球的重力加速度，
    Figure PCTCN2017100128-appb-100002
    为等效内马氏瓶中空气的压力值随时间的变化率；
    电脑终端(8)根据所述数据采集卡(7)提供的所述等效马氏瓶中空气的真空压力值的数字信号生成离散的
    Figure PCTCN2017100128-appb-100003
    值，再根据离散的
    Figure PCTCN2017100128-appb-100004
    值生成P-t曲线。
  7. 根据权利要求5或6所述的量程可调式双环入渗装置进行的土壤渗透 系数的原位测试方法，其特征在于：P-t曲线纵坐标除以常数ρg转化得到V-t曲线。
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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110031380A (zh) * 2019-05-21 2019-07-19 科利尔环保科技有限责任公司 一种现场无损测量多孔混凝土渗透速率的方法
CN110595984A (zh) * 2019-10-29 2019-12-20 兰州理工大学 一种测量原状土饱和导水率的圆筒入渗仪及其测量方法
CN112683731A (zh) * 2021-01-27 2021-04-20 山东理工大学 一种组合式多深度土壤容重测量器及试验方法
CN113655198A (zh) * 2021-07-30 2021-11-16 长江大学 一种测试原位淋溶土壤有机质组分变化的试验装置及方法
CN117169089A (zh) * 2023-11-03 2023-12-05 东北农业大学 一种土壤渗透率检测的张力入渗仪

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110702572B (zh) * 2019-09-29 2022-09-02 郑琼 一种土壤入渗自动补水和测量装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN202793984U (zh) * 2012-06-25 2013-03-13 西安理工大学 野外入渗仪
JP5433885B1 (ja) * 2012-12-11 2014-03-05 強化土株式会社 地盤改良工法
CN104535476A (zh) * 2015-01-29 2015-04-22 北京市水文地质工程地质大队 一种野外土壤入渗实验实时监测装置
CN204314189U (zh) * 2014-12-08 2015-05-06 上海大学 一种水位可控式渗流模型试验箱
CN205808881U (zh) * 2016-05-16 2016-12-14 南京工业大学 一种自动进水控制透水路面现场双环透水性测试装置
CN106525682A (zh) * 2016-10-26 2017-03-22 中国地质大学（北京） 一种原位测定沉积物垂向渗透系数的方法及实验装置

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN202793984U (zh) * 2012-06-25 2013-03-13 西安理工大学 野外入渗仪
JP5433885B1 (ja) * 2012-12-11 2014-03-05 強化土株式会社 地盤改良工法
CN204314189U (zh) * 2014-12-08 2015-05-06 上海大学 一种水位可控式渗流模型试验箱
CN104535476A (zh) * 2015-01-29 2015-04-22 北京市水文地质工程地质大队 一种野外土壤入渗实验实时监测装置
CN205808881U (zh) * 2016-05-16 2016-12-14 南京工业大学 一种自动进水控制透水路面现场双环透水性测试装置
CN106525682A (zh) * 2016-10-26 2017-03-22 中国地质大学（北京） 一种原位测定沉积物垂向渗透系数的方法及实验装置

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110031380A (zh) * 2019-05-21 2019-07-19 科利尔环保科技有限责任公司 一种现场无损测量多孔混凝土渗透速率的方法
CN110595984A (zh) * 2019-10-29 2019-12-20 兰州理工大学 一种测量原状土饱和导水率的圆筒入渗仪及其测量方法
CN112683731A (zh) * 2021-01-27 2021-04-20 山东理工大学 一种组合式多深度土壤容重测量器及试验方法
CN113655198A (zh) * 2021-07-30 2021-11-16 长江大学 一种测试原位淋溶土壤有机质组分变化的试验装置及方法
CN113655198B (zh) * 2021-07-30 2024-03-15 长江大学 一种测试原位淋溶土壤有机质组分变化的试验装置及方法
CN117169089A (zh) * 2023-11-03 2023-12-05 东北农业大学 一种土壤渗透率检测的张力入渗仪
CN117169089B (zh) * 2023-11-03 2024-01-26 东北农业大学 一种土壤渗透率检测的张力入渗仪

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