CN102937545B - Method for maintaining constant degree of saturation of test soil body - Google Patents
Method for maintaining constant degree of saturation of test soil body Download PDFInfo
- Publication number
- CN102937545B CN102937545B CN201210447782.4A CN201210447782A CN102937545B CN 102937545 B CN102937545 B CN 102937545B CN 201210447782 A CN201210447782 A CN 201210447782A CN 102937545 B CN102937545 B CN 102937545B
- Authority
- CN
- China
- Prior art keywords
- soil body
- moisture
- test
- soil
- air
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
Abstract
The invention provides a method for maintaining constant degree of saturation of a test soil body and aims to solve the problems that in prior art, the maintenance of the degree of saturation of the test soil body is random and the accurate degree of the test is low. The method includes placing the test soil body in enclosed space; testing the initial temperature and humidity of the air above the soil body, and calculating to obtain an initial air moisture content V1; testing to obtain the relative humidity of current air when the temperature rises to a certain degree, inquiring the dew point temperature which corresponds to the air humidity, and calculating to obtain a current air moisture content V2; calculating a differential value delta V of the current moisture content V2 and an initial moisture content V3 to serve as evaporation amount of moisture in the soil body; and supplementing delta V of moisture into the soil body so as to maintain the constant degree of saturation of the soil body. By means of the method, moisture is accurately supplemented to the soil body, the constant degree of saturation of the soil body can be simply and effectively maintained, and thereby the test result of the experiment is objective, real and reliable.
Description
Technical field
The present invention relates to the test method of a kind of unsaturated soil in civil engineering work soil test field, particularly relate to and a kind ofly keep the test method that unsaturated soil saturation degree is constant.
Background technology
Natural rock-filled is a kind of three-phase material system of complexity, and wherein soil particle forms solid soil skeleton, and soil skeleton is filled with liquids and gases between space, and the space between skeleton is all that liquid is full of, then form saturated soil; If the aperture sections of inside soil body is full of by liquid, then it is unsaturated soil.Unsaturated soil is a kind of non-homogeneous porous medium material be made up of soil particle and not miscible fluid (as water---gas, water---oil, water---pollutant etc.), and it is extensively distributed in soil-slope, earth and rockfill dam, Roadbed Soil, refuse landfill and arid---among semiarid zone.Along with national economy improves constantly transport need, highway, railway construction expanding day, the unsaturated soil such as fine grained soil (slity soil and clayey soil), swelled ground, loess and collapsible soil also increases gradually as roadbed material.In the last few years, along with the fast development of China's economy and the aggravation of human society transformation activity, more and more engineering problem relevant with unsaturated soil has to be solved.
Build the subgrade engineering in unsaturated soil area, hydraulic engineering and municipal works etc., owing to being subject to the factor impacts such as such as weather, shallow-layer unsaturated soil engineering properties changes, and shows as and constructs water in engineering, heat distribution change.This change has significant impact to engineering stability, and often cause subgrade engineering to occur the diseases such as depression, vertical swollen, ditch falls, hydraulic engineering occurs that the diseases such as frost heave, depression, check crack appear in the diseases such as frost heave, bank slump, cracking of building body, municipal works.Disease causes is that in soil, water cut increases generation saturated yielding, and intensity reduces, and freeze thawing makes native own vol change, and male and female face Shang Shui, hot difference cause uneven deformation etc., and affecting shallow-layer unsaturated soil engineering stability leading indicator is water cut and temperature.
Have the impact of the engineering stability such as unsaturated soil roadbed engineering, hydraulic engineering of certain soil body saturation degree to accurately grasp, people need with this unsaturated soil for experimental subjects carries out the test of the hydraulic parameters such as soil solidifying, viscoelasticity.Carrying out in the middle of every process of the test of the soil body, the change due to environment temperature can cause the loss of moisture in the soil body, thus causes soil body saturation degree to change, and affects the accuracy of test findings.Therefore, in experimentation, keep that soil body saturation degree is constant just seems extremely important.
In order to keep soil body saturation degree constant, in prior art, general employing adds water to keep the way of soil body saturation degree directly in the test soil body.But this way has larger randomness, soil body saturation degree is stable not, thus is unfavorable for obtaining experimental result accurately.
Summary of the invention
The object of the present invention is to provide and a kind ofly keep the method that unsaturated soil saturation degree is constant, to overcome in prior art the randomness keeping soil body saturation degree, improve the order of accuarcy of test.
The present inventor is found by a large amount of experiments:
1, the physical process of soil body moisture evaporation
The condition that soil body moisture evaporation continuation carries out is: often have heat to arrive native face, provides the heat of vaporization needed for moisture vaporization; Soil face vapour pressure is higher than atmospheric water vapour pressure; Soil face can continue to obtain moisture in soil.According to the motion conditions of various form moisture, soil body moisture evaporation process divides three phases:
1. the kapillary operation phase, when the soil body is moistening, water is full of inside soil body hole, and moisture, by capillarity, constantly runs to earth's surface rapidly, and moisture is in earth's surface vaporization, diffusion, and the evaporation of soil body moisture is strong.
2. the film operation phase, when evaporation water consumption makes water content of soil reduce, when being less than capillary water fracture water cut, capillary water disconnects, and capillary conductivity stops, and soil body moisture is then with pellicular water form, moves to the place that moisture film is thin in the place thick by moisture film.Because this motion is slow, moisture evaporation obviously weakens.Now, evaporation is not only carried out on earth's surface, and inside soil body moisture also can be vaporized, and through soil body hole to atmospheric diffusion.
3. spread the operation phase, when water content of soil reduces, during close to wilting coefficient, soil body moisture is stopped substantially by the film movement of bottom to native face, only has vaporous water to spread in the soil body of earth's surface, and rate of evaporation is very little.
2, the influence factor of soil body moisture evaporation
Except the same factor affecting evaporation from water surface, still there are water content of soil, bury of groundwater, soil structures, soil body color and luster, soil body surface feature etc.
1. when water content of soil is close to time saturated, because irregular soil body particle constitutes larger total evaporation surface, the rapid steamer meeting of the free-water level that rapid steamer can be more identical than horizontal area is many.In the cm range of soil body top layer 3 ~ 5, water cut plays a decisive role to evaporation, down affects less.
If 2. bury of groundwater is little, phreatic table often remains within the scope of capillarity, then water content of soil can be supplemented enduringly, and evaporation evenly; Otherwise, if bury of groundwater is large, then the vary within wide limits of rate of evaporation reduction.
3. the soil body of crumb structure, evaporation capacity is little; The soil body of non-crumb structure, evaporation capacity is large.
4. soil body color change soil body surface reflectivity, thus impact evaporation, soil body color is darker, and evaporation capacity is larger.The evaporation capacity of the brown soil body is than large 19% of white, and the evaporation capacity of the black soil body is than large 32% of white.
5. soil body surface feature affects the turbulent fluctuation effect of wind, large than level and smooth ground of the evaporation capacity of rough earth; Topological highs wind speed is large, and highland evaporation capacity is larger than basin; Earth's surface slope aspect is different, and affect radiation-absorbing, evaporation capacity is also different.
Visible, as shown in Figure 1, along with the rising of ambient temperature, the moisture on soil body top, under evaporation, constantly enters in the middle of air with vapor form; Because soil body top moisture reduces, bottom moisture under capillary action, to soil body ionized motion, causes underground water table constantly to decline.As shown in Figure 2, due in the process that raises in temperature, the moisture entered in air gets more and more, and the humidity of air strengthens thereupon, and the water loss in the soil body is serious, directly causes the saturation degree of the soil body to decline.Therefore, can consider that the humidity by adjusting air keeps the invariable of soil body saturation degree.
Accordingly, method of the present invention comprises the following steps: the test soil body is placed in a confined space; Test out initial temperature and the humidity of the air on soil body top, calculate initial air moisture content V1; When temperature rises to a certain degree, test obtains the relative humidity of present air, the dewpoint temperature that inquiry follows air humidity corresponding, calculates current air moisture content V2; Calculate the difference △ V of current water cut V2 and initial water content V3, be the evaporation capacity of moisture in the soil body; The moisture of the △ V water yield is filled into the soil body, to keep the constant of the saturation degree of the soil body.
According to method of the present invention, further comprising the steps of: to form simulate formation water layer in advance in confined space bottom.
According to method of the present invention, the moisture of the △ V water yield is filled into the soil body by the mode preferably by artificial spray.
According to method of the present invention, when preferably moisture is in the kapillary operation phase in the soil body, carry out moisturizing, thus make the water energy Quick uniform filled into dissolve in the soil body.
Adopting method of the present invention by accurately keeping the skin wet to the soil body, can simply, effectively keep soil body saturation degree constant, thus make the test result of experiment more objective, true, reliable.
Accompanying drawing explanation
Fig. 1 is soil body water translocation schematic diagram under high temperature;
Fig. 2 is according to soil body water translocation schematic diagram after the method for the invention moisturizing.
Embodiment
Below in conjunction with accompanying drawing, to the concrete enforcement of the method for the invention, details are as follows:
1. simulate formation water layer is set in the bottom, space of a cuboid;
2. place the test soil body on water table top, form the soil body;
3. airtight described cuboid space;
4. test out initial temperature and the humidity of the air on confined space top, calculate the air moisture content V1 above the soil body;
5. temperature is elevated to a certain degree, tests the humidity, temperature and the dewpoint temperature that obtain present air, calculates the water cut V2 of present air;
6. calculate the difference △ V between V1 and V2, be the evaporation capacity of moisture in the soil body;
7., during the moisture in the soil body is also in the kapillary operation phase, the water yield of △ V is evenly sprayed soil body surface by the mode of artificial spray, thus keeps the constant of the saturation degree of the soil body.
The present invention can summarize with other the concrete form without prejudice to spirit of the present invention or principal character.Therefore, no matter from which point, above-mentioned embodiment of the present invention all can only be thought explanation of the present invention and can not limit the present invention.Claims indicate scope of the present invention, and scope of the present invention is not pointed out in above-mentioned explanation.Therefore, any change in the implication suitable with claims of the present invention and scope, all should think to be included in the scope of claims.
Claims (4)
1. keep the method that the saturation degree of the test soil body is constant, it is characterized in that comprising the following steps:
(1) the test soil body is placed in a confined space, forms the soil body;
(2) test out initial temperature and the humidity of the air on described soil body top, calculate initial air moisture content V1;
(3) when temperature rises to a certain degree, test out current air humidity, temperature and dewpoint temperature, calculate current air moisture content V2;
(4) calculate the difference △ V of current water cut V2 and initial water content V1, be the evaporation capacity of moisture in the soil body;
(5) moisture of the △ V water yield is filled into the soil body, keep the constant of the saturation degree of the soil body.
2. method according to claim 1, characterized by further comprising following steps: before step (1), forms simulate formation water layer in described confined space bottom.
3. method according to claim 2, is characterized in that: in step (5), by the mode manually sprayed, the moisture of the △ V water yield is filled into the described soil body.
4. method according to claim 3, is characterized in that: manually spray moisturizing when the moisture in the described soil body is in the kapillary operation phase.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210447782.4A CN102937545B (en) | 2012-11-12 | 2012-11-12 | Method for maintaining constant degree of saturation of test soil body |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210447782.4A CN102937545B (en) | 2012-11-12 | 2012-11-12 | Method for maintaining constant degree of saturation of test soil body |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102937545A CN102937545A (en) | 2013-02-20 |
| CN102937545B true CN102937545B (en) | 2015-03-04 |
Family
ID=47696456
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210447782.4A Expired - Fee Related CN102937545B (en) | 2012-11-12 | 2012-11-12 | Method for maintaining constant degree of saturation of test soil body |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102937545B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106290801B (en) * | 2016-10-27 | 2018-06-19 | 中南大学 | The device and method of soil body saturation degree control |
| CN110736761B (en) * | 2019-09-28 | 2020-10-02 | 同济大学 | Visual test device and method for influence of temperature change on subway tunnel |
| CN114167032B (en) * | 2021-11-29 | 2024-05-14 | 内蒙古科技大学 | Method and device for simulating influence of mining subsidence on soil water salt migration |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101957360A (en) * | 2010-09-10 | 2011-01-26 | 北京大学 | Method and system for measuring surface evapotranspiration quantity |
| CN202095371U (en) * | 2011-06-03 | 2012-01-04 | 李崇平 | Automatic spray system |
| CN102353602A (en) * | 2011-06-15 | 2012-02-15 | 中国水利水电科学研究院 | Compensating automatic measurement system and method of soil surface evaporation capacity |
| CN102696433A (en) * | 2012-07-02 | 2012-10-03 | 昆山卉友生态科技有限公司 | Automatic-irrigation heat-insulating cultivation box for plant cultivation |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2694399C (en) * | 2009-02-25 | 2016-11-01 | Ramanathan Sri Ranjan | Plant-controlled atmometer for measuring crop evapotranspiration |
-
2012
- 2012-11-12 CN CN201210447782.4A patent/CN102937545B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101957360A (en) * | 2010-09-10 | 2011-01-26 | 北京大学 | Method and system for measuring surface evapotranspiration quantity |
| CN202095371U (en) * | 2011-06-03 | 2012-01-04 | 李崇平 | Automatic spray system |
| CN102353602A (en) * | 2011-06-15 | 2012-02-15 | 中国水利水电科学研究院 | Compensating automatic measurement system and method of soil surface evaporation capacity |
| CN102696433A (en) * | 2012-07-02 | 2012-10-03 | 昆山卉友生态科技有限公司 | Automatic-irrigation heat-insulating cultivation box for plant cultivation |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102937545A (en) | 2013-02-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Zhang et al. | Interaction of soil water storage dynamics and long-term natural vegetation succession on the Loess Plateau, China | |
| Zhou et al. | Monitoring and modeling the influence of snow pack and organic soil on a permafrost active layer, Qinghai–Tibetan Plateau of China | |
| Schwank et al. | Microwave L-band emission of freezing soil | |
| CN106645633B (en) | The deformation simulative device and analogy method of dilative soil roadbed under dry wet alternating environment | |
| Wang et al. | Effects of a thaw slump on active layer in permafrost regions with the comparison of effects of thermokarst lakes on the Qinghai–Tibet Plateau, China | |
| Zhao et al. | A parametric expression for estimating infiltration into frozen soils | |
| CN102937545B (en) | Method for maintaining constant degree of saturation of test soil body | |
| Xia et al. | Simulation of freezing and melting of soil on the northeast Tibetan Plateau | |
| Meng et al. | Simulated regional transport structures and budgets of dust aerosols during a typical springtime dust storm in the Tarim Basin, Northwest China | |
| Hu et al. | Modeling hydrothermal transfer processes in permafrost regions of Qinghai-Tibet Plateau in China | |
| Chou et al. | Seasonal freezing-thawing process and hydrothermal characteristics of soil on the Loess Plateau, China | |
| CN103116695A (en) | Urban area water logging flood processing simulation method based on CD-TIN | |
| CN102928575B (en) | Device capable of keeping saturation of experimental soil mass constant | |
| Wang et al. | Mechanisms and influencing factors of hydrothermal processes in active layer soils on the Qinghai-Tibet Plateau under freeze–thaw action | |
| Fan et al. | Effect of soil properties on Hydraulic characteristics under subsurface drip irrigation | |
| Li et al. | Unsaturated hydraulic conductivity in limestone dolines: Influence of vegetation and rock fragments | |
| Parde et al. | Improving simulation of the fog life cycle with high-resolution land data assimilation: A case study from WiFEX | |
| Fu et al. | Response of soil hydrothermal processes within the active layer to variable alpine vegetation conditions on the Qinghai‒Tibet Plateau | |
| CN202133659U (en) | Experimental device for monitoring swelling-shrinkage deformation of deep soil under influence of hot rainy weather | |
| Wang et al. | Effect of a thermokarst lake on soil physical properties and infiltration processes in the permafrost region of the Qinghai-Tibet Plateau, China | |
| Joel et al. | Infiltration rate and hydraulic conductivity measured with rain simulator and disc permeameter on sloping arid land | |
| Ya-ling et al. | Seasonal freezing-thawing process and hydrothermal characteristics of soil on the Loess Plateau, China | |
| Araki et al. | Changes of vertical soil moisture conditions of a dry evergreen forest in Kampong Thom, Cambodia | |
| Wang et al. | Hydrological effect of urbanization in Yitong River Basin | |
| Zhao et al. | Variation characteristics and effects of splash erosion on slope micro-relief in bare fields |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150304 Termination date: 20161112 |