scholarly journals Sask method for testing hydraulic conductivity of soils by flat dilatometer (dmt)

2012 ◽  
Vol 34 (3) ◽  
pp. 63-72 ◽  
Author(s):  
Kazimierz Garbulewski ◽  
Stanisław Żakowicz ◽  
Simon Rabarijoely ◽  
Anna Łada
Keyword(s):  
Hydraulic Conductivity ◽  
Water Pressure ◽  
Clay Soils ◽  
Soil Parameters ◽  
Time Varying ◽  
Laboratory Measurements ◽  
Outcome Parameter ◽  
Experimental Site ◽  
Measuring Time ◽  
Soil And Water

Abstract DMT is one of the most popular methods of determining soil parameters needed to design a safe construction. Apart from the basic outcome parameter obtained from DMT measurements hydraulic conductivity (k) can be determined, previously proposed DMTA and DMTC methods were modified. The basic idea of the method is that the return of the deformed membrane is due to soil and water pressure. In the proposed SASK method the hydraulic conductivity of the soil is determined by measuring time-varying pressures A and C. Research has been performed at the experimental site of the Department of Geotechnical Engineering, WULS. In the paper, the assumptions of the new method for determining the hydraulic conductivity k are presented. The proposed method allows us to determine a reliable value for the hydraulic conductivity of clay soils. Using this method, the value of hydraulic conductivity (k = 5,47*10-11) is similar to the results of BAT, DMTA and laboratory measurements.

Saturated Hydraulic Conductivity of Clayey Tills and the Role of Fractures

1990 ◽  
Vol 21 (2) ◽  
pp. 119-132 ◽  
Author(s):  
Johnny Fredericia
Keyword(s):  
Hydraulic Conductivity ◽  
American Studies ◽  
Field Measurements ◽  
Present Knowledge ◽  
Saturated Hydraulic Conductivity ◽  
Field Observations ◽  
Laboratory Measurements ◽  
Vertical Hydraulic Conductivity ◽  
Data Field

The background for the present knowledge about hydraulic conductivity of clayey till in Denmark is summarized. The data show a difference of 1-2 orders of magnitude in the vertical hydraulic conductivity between values from laboratory measurements and field measurements. This difference is discussed and based on new data, field observations and comparison with North American studies, it is concluded to be primarily due to fractures in the till.

scholarly journals The research of dynamic impacts on the hydraulic structure foundation base, transformed in the process of accident recovery

2018 ◽  
Vol 251 ◽  
pp. 04040
Author(s):  
Zaven Ter-Martirosyan ◽  
Ivan Luzin
Keyword(s):  
Field Experiments ◽  
Dynamic Properties ◽  
Soil Parameters ◽  
Experimental Site ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Foundation Base ◽  
Dynamic Impacts ◽  
Scale Experiment ◽  
Selection Of

The article presents the results of a comprehensive research of the dynamic impacts on a modified base. The modified base was obtained as a result of compensatory injection at the experimental site for the accident recovery at the hydraulic engineering structure. The complex study of the dynamic impacts includes special laboratory tests to determine the soil parameters, the finite element analysis of the experimental site, taking into account the dynamic properties, the selection of the necessary equipment for field experiments based on the numerical solution results, a full-scale experiment with the measurement of the foundation sediments of the experimental site.

scholarly journals Hydraulic and Swell–Shrink Characteristics of Clay and Recycled Zeolite Mixtures for Liner Construction in Sustainable Waste Landfill

2021 ◽  
Vol 13 (13) ◽  
pp. 7301
Author(s):  
Marcin K. Widomski ◽  
Anna Musz-Pomorska ◽  
Wojciech Franus
Keyword(s):  
Hydraulic Conductivity ◽  
Exchange Capacity ◽  
Saturated Hydraulic Conductivity ◽  
Clay Soils ◽  
Compacted Clay ◽  
Clay Liner ◽  
Compacted Clay Liner ◽  
Drying And Rewetting ◽  
Swelling Characteristics ◽  
Shrinkage And Swelling

This paper presents research considering hydraulic as well as swelling and shrinkage characteristics of potential recycled fine particle materials for compacted clay liner for sustainable landfills. Five locally available clay soils mixed with 10% (by mass) of NaP1 recycled zeolite were tested. The performed analysis was based on determined plasticity, cation exchange capacity, coefficient of saturated hydraulic conductivity after compaction, several shrinkage and swelling characteristics as well as, finally, saturated hydraulic conductivity after three cycles of drying and rewetting of tested specimens and the reference samples. The obtained results showed that addition of zeolite to clay soils allowed reduction in their saturated hydraulic conductivity to meet the required threshold (≤1 × 10−9 m/s) of sealing capabilities for compacted clay liner. On the other hand, an increase in plasticity, swelling, and in several cases in shrinkage, of the clay–zeolite mixture was observed. Finally, none of the tested mixtures was able to sustain its sealing capabilities after three cycles of drying and rewetting. Thus, the studied clayey soils mixed with sustainable recycled zeolite were assessed as promising materials for compacted liner construction. However, the liner should be operated carefully to avoid extensive dissication and cracking.

scholarly journals Analysis of Seepage Characteristics of a Foundation Pit with Horizontal Waterproof Curtain in Highly Permeable Strata

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1303
Author(s):  
Chenghua Shi ◽  
Xiaohe Sun ◽  
Shengli Liu ◽  
Chengyong Cao ◽  
Linghui Liu ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Theoretical Calculation ◽  
Calculation Method ◽  
Design Method ◽  
Water Pressure ◽  
Water Inflow ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Seepage Characteristics

At present, jet-grouted horizontal waterproof curtain reinforcement has become an essential method for deep foundation pit groundwater control. However, there is still a lack of an effective theoretical calculation method for horizontal waterproof curtain reinforcement, and there is little research on the seepage laws of foundation pits under different horizontal waterproof curtain conditions. Based on Darcy’s seepage theory, theoretical analysis models of deep foundation pit seepage were established considering the effect of a horizontal curtain in a highly permeable formation. Through the established models, the calculation method of the water inflow and the water pressure under the condition of a horizontal curtain was derived. Then through indoor tests, the reliability of the theoretical calculation method was verified. Furthermore, the established theoretical calculation method is used to analyze the influence of various factors on the water inflow and the water pressure, such as the ratio of hydraulic conductivity of the horizontal curtain to surrounding soil, thickness, and reinforcement position of the horizontal curtain. It is found that the hydraulic conductivity ratio has the most significant influence on the seepage characteristics of the foundation pit. Finally, the design method was applied to an example of the horizontal waterproof curtain of the foundation pit, which is located at Juyuanzhou Station in Fuzhou (China). The water inflow per unit area is 0.36 m3/d in the foundation pit, and this implies that the design method of the horizontal waterproof curtain applied for the excavation case is good and meets the requirements of design and safety.

Estimation and Scaling of the Near-Saturated Hydraulic Conductivity

1999 ◽  
Vol 30 (3) ◽  
pp. 177-190 ◽  
Author(s):  
Per Atle Olsen
Keyword(s):  
Hydraulic Conductivity ◽  
Saturated Hydraulic Conductivity ◽  
Scaling Analysis ◽  
Laboratory Measurements ◽  
Estimation Errors ◽  
Geometric Means ◽  
Top Soil ◽  
Structured Soils ◽  
Order Of Magnitude

The hydraulic conductivity in structured soils is known to increase drastically when approaching saturation. Tension infiltration allows in situ infiltration of water at predetermined matric potentials, thus allowing exploration of the hydraulic properties near saturation. In this study, the near saturated (ψ≥-0.15 m) hydraulic conductivity was estimated both in the top- and sub-soil of three Norwegian soils. A priory analysis of estimation errors due to measurement uncertainties was conducted. In order to facilitate the comparison between soils and depths, scaling analysis was applied. It was found that the increase in hydraulic conductivity with increasing matric potentials (increasing water content) was steeper in the sub-soil than in the top-soil. The estimated field saturated hydraulic conductivity was compared with laboratory measurements of the saturated hydraulic conductivity. The geometric means of the laboratory measurements was in the same order of magnitude as the field estimates. The variability of the field estimates of the hydraulic conductivity from one of the soils was also assessed. The variability of the field estimates was generally smaller than the laboratory measurements of the saturated hydraulic conductivity.

The relationship between aggregation and other soil properties in cracking clay soils

Soil Research ◽  
1984 ◽  
Vol 22 (1) ◽  
pp. 59 ◽  
Author(s):  
KJ Coughlan ◽  
RJ Loch
Keyword(s):  
Hydraulic Conductivity ◽  
Salt Content ◽  
Chemical Properties ◽  
Aggregate Size ◽  
Strong Relationship ◽  
Clay Soils ◽  
Coarse Surface ◽  
Seedbed Preparation ◽  
The Relationship ◽  
Dispersion Ratio

This paper explores the processes responsible for clay dispersion, and the formation of large dry aggregates, in cracking clay soils. It also isolates the soil factors causing variations in dry aggregate size using regression analysis. Twelve cracking clay soil samples were selected on visual differences in dry aggregate size distribution following seedbed preparation, and a range of soil structural and chemical properties were measured. The per cent dry aggregates > 5 mm was found to increase with resistance to mechanical abrasion, stability to wet sieving after capillary wetting, and dispersion ratio, indicating that large dry aggregates are formed as a result of binding by dispersed clay. Both raindrop impact and puddling by cultivation may be involved in dispersion. There was a strong relationship between dry aggregate size in the 0-10 cm layer and salt content in the subsurface (60-90 cm) layer. Coarse surface aggregation is explained in terms of limited profile hydraulic conductivity. For the soils studied, the properties of the surface layer appear to be responsible, at least in part, for the limitation in profile hydraulic conductivity. Dry aggregate size in the 0-10 cm layer was not simply correlated with any of the chemical properties of that layer. However, equations containing two (ESP and CEC per gram of clay) or three (ESP, per cent clay and CEC) independent variables were derived to explain variations in dry aggregate size, both for the 12 soils studied and for a wider range of Queensland cracking clay soils.

scholarly journals Application of the SWAT (Soil and Water Assessment Tool) model in the Ronnea catchment of Sweden

2013 ◽  
Vol 7 (3) ◽  
pp. 252-257
Keyword(s):  
Input Data ◽  
Management Practices ◽  
Assessment Tool ◽  
Swat Model ◽  
Soil Parameters ◽  
Daily Step ◽  
Calibration And Validation ◽  
The Impact ◽  
Water Assessment ◽  
Soil And Water

The subject of this article is the estimation of quantitative (hydrological) and qualitative parameters in the catchment of Ronnea (1800 Km2, located in south western Sweden) through the application of the Soil and Water Assessment Tool (SWAT). SWAT is a river basin model that was developed for the U.S.D.A. Agricultural Research Service, by the Blackland Research Center in Texas. The SWAT model is a widely known tool that has been used in several cases world-wide. It has the ability to predict the impact of land management practices on water, sediment and agricultural chemical yield in large complex watersheds. The present work investigates certain capabilities of the SWAT model which have not identified up to now. More in specific, the main targets of the work carried out are the following: • Identification of the existing hydrological and qualitative conditions • Preparation - Processing of data required to be used as input data of the model • Hydrological calibration - validation of the model, in 7 subbasins of the Catchment of Ronnea • Estimation and evaluation of the simulated qualitative parameters of the model All available data were offered by the relevant Institutes of Sweden, in the framework of the European program EUROHARP. The existing conditions in the catchment of Ronnea, are described in detail including topography, land uses, soil types, pollution sources, agricultural management practices, precipitation, temperature, wind speed, humidity, solar radiation as well as observed discharges and Nitrogen and Phosphorus substances concentrations. Most of the above data were used as input data for the application of SWAT model. Adequate methods were also used to complete missing values in time series and estimate additional parameters (such as soil parameters) required by the model. Hydrological calibration and validation took place for each outlet of the 7 subbasins of Ronnea catchment in an annual, monthly and daily step. The calibration was achieved by estimating parameters related to ground water movement and evaluating convergence between simulated and observed discharges by using mainly the Nash & Sutcliffe coefficient (NTD). Through the sensitivity analysis, main parameters of the hydrological simulation, were detected. According to the outputs of the SWAT model, the water balance of Ronnea catchment was also estimated. Hydrological calibration and validation is generally considered sufficient in an annual and monthly step. Hydrological calibration – validation in daily step, generally does not lead to high values of the NTD indicator. However, when compared to results obtained by the use of SWAT in Greece, a relatively high value of NTD is achieved in one subbasin. Finally, a comparison between the simulated and observed concentrations of total Phosphorus and Nitrogen was carried out.

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