scholarly journals ANALISIS PERBANDINGAN NILAI KOEFISIEN PERMEABILITAS TANAH UJI LAPANGAN DAN UJI LABORATORIUM

2020 ◽  
Vol 3 (1) ◽  
pp. 97
Author(s):  
Philip Chen ◽  
Gregorius Sandjadja Sentosa
Keyword(s):  
Initial Data ◽  
Permeability Coefficient ◽  
Laboratory Tests ◽  
Pumping Test ◽  
Soil Permeability ◽  
Pumping Tests ◽  
Final Project ◽  
Coefficient Of Permeability ◽  
The Difference ◽  
Constant Head

The coefficient of permeability (k) results of pumping tests are used as initial data to determine the rate of water seepage in the soil, determining the permeability capability of the soil can be done by measurements in the laboratory and in the field. In reality the permeability coefficient value of field test is not the same as the test in the laboratory. This final project will analyze the difference in value (k) obtained from field and laboratory tests in order to enrich the data in determining the value of permeability coefficient (k). The analysis uses Thiem and Theis method in analyzing the results of pumping tests. And using constant head permeameter to determine the value of the coefficient of permeability (k) in laboratory. From the analysis results obtained by the Thiem method, the permeability coefficient (k) obtained is in the range of  6,8x cm/sec - 2,8x cm/sec, and Theis method is obtained in the range of  6,03x cm/sec - 6,03x cm/sec. Meanwhile the results of the coefficient of soil permeability (k) by the laboratory tests using the constant head permeameter is in the range 1,43x  cm/sec - 8,76x cm/sec. And for calculations using the Hazen method the result is in the range 8,71x cm/sec - 4,35x cm/sec.AbstrakNilai koefisien permeabilitas (k) hasil pumping test digunakan sebagai data awal untuk mengetahui kecepatan rembesan air di dalam tanah, penentuan kemampuan permeabilitas tanah dapat dilakukan dengan pengukuran di laboratorium dan di lapangan. Dalam kenyataannya nilai koefisien permeabilitas uji lapangan biasanya tidak sama dengan uji di laboratorium. Penelitian ini akan menganalisa perbedaan nilai (k) yang didapat dari uji lapangan dan uji laboratorium guna memperkaya data dalam menentukan nikai koefisien permeabilitas (k). Analisa pada penelitian ini menggunakan metode Thiem dan metode Theis dalam menganalisa hasil pumping test pada lapangan. Dan menggunakan constant head permeameter sebagai alat menentukan nilai koefisien permeabilitas (k) pada laboratorium. Serta menggunakan metode rumus empiris Hazen untuk menentukan nilai koefisien permeabilitas (k) berdasarkan ukuran butiran. Dari hasil analisis yang diperoleh dengan metode Thiem nilai koefisien permeabilitas (k) yang didapat berada pada rentang  6,8x m/detik - 2,8x cm/detik, dan dengan metode Theis didapat pada rentang 6,03x cm/detik - 6,03x cm/detik. Sedangkan hasil uji laboratorium menggunakan permeameter constant head mendapatkan hasil nilai koefisien permeabilitas tanah (k) pada rentang 1,43x  cm/detik  -   8,76x cm/detik. Dan didapat hasil 8,71x cm/detik - 4,35x cm/detik untuk perhitungan menggunakan metode Hazen.

scholarly journals Tinjauan Nilai Permeabilitas Tanah Tanggul Canal Blocking

2019 ◽  
Vol 3 (1) ◽  
pp. 7-14
Author(s):  
Muhammad Amad Arifin ◽  
Fathurrozie Fathurrozie
Keyword(s):  
Permeability Coefficient ◽  
Peat Soil ◽  
Soil Permeability ◽  
Technical Problems ◽  
Final Project ◽  
Local Soil ◽  
Technical Properties ◽  
Constant Head ◽  
Properties Of Soil

Air sangat berpengaruh pada sifat-sifat teknis tanah dan juga air berperan sangat penting dalam masalah-masalah teknis yang berhubungan dengan tanah yaitu permeabilitas. Permeabilitas tanah yaitu kecepatan air yang menembus tanah pada periode tertentu dan dinyatakan dalam cm/jam. Nilai permeabilitas sangat penting dalam menentukan penggunaan dan pengelolaan praktis tanah. Koefisien permeabilitas tanah memiliki nilai yang berbeda untuk berbagai jenis tanah. Ada dua macam alat untuk menentukan nilai permeabilitas, yaitu constant head permeameter dan  falling head permeameter. Lokasi penelitian tanggul canal blocking berada di Hutan Lindung Liang Anggang yang terletak di Kecamatan Liang Anggang, Kota Banjarbaru, Provinsi Kalimantan Selatan. Dimana tubuh tanggul canal blocking menggunakan tanah urugan setempat (tanah gambut) dijadikan tubuh tanggul canal blocking. Tugas Akhir ini menggunakan metode survei dan pengambilan data tanah pada kawasan tanggul canal blocking. Bila dilihat nilai permeabilitasnya pada tubuh tanggul yang didapat, termasuk kelas sangat rendah yaitu kurang < 0,125 cm/jam. Jadi penggunaan tanah urugan setempat untuk dijadikan tubuh tanggul sudah cukup efektif . Water is very influential on the technical properties of soil and also water plays a very important role in the technical problems related to soil, namely permeability. Soil permeability is the speed of water that penetrates the soil in a certain period and is expressed in cm / hour. Permeability values ​​are very important in determining the practical use and management of land. The soil permeability coefficient has different values ​​for various types of soil. There are two types of tools for determining permeability values, namely constant permeability head and permeability falling head. The research location of the canal blocking dikes is in the Liang Anggang Protected Forest located in Liang Anggang District, Banjarbaru City, South Kalimantan Province. Where the canal blocking embankment body uses local soil (peat soil) as a canal blocking embankment body. This Final Project uses a survey and retrieval of soil data in the canal blocking embankment area. If you see the permeability value on the embankment body obtained, including the class is very low, which is less than 0.125 cm / hour. So the use of local land to be used for embankment is quite effective.

scholarly journals Measurement of hydraulic conductivity under horizontal paths in granular soils

Respuestas ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 92-101
Author(s):  
Maria Fernanda García ◽  
Camilo Andres Aldana ◽  
Allex Fabrizio López ◽  
Juan Carlos Ruge C. ◽  
Eliana Martinez Rojas
Keyword(s):  
Hydraulic Conductivity ◽  
Permeability Coefficient ◽  
Point Of View ◽  
Granular Soils ◽  
Physical Point ◽  
Soil Layers ◽  
Coefficient Of Permeability ◽  
Geotechnical Structures ◽  
The Difference ◽  
Constant Head

In geotechnical structures, the permeability-dependent stability analysis is generally evaluated under vertical trajectories, because most permeameters are configured so that the water passes through the porous medium in this way. However, it is clear from the physical point of view that water can flow along different paths, including preferential ways that can include horizontal trajectories, parallel to the deposit of the stratum. The foregoing implies that both the vertical and horizontal component of the hydraulic conductivity or permeability coefficient must be estimated for a given stratum. The current research aims to explore possibilities for measuring the coefficient of permeability in horizontal trajectories, on granular soils, under a constant condition of relative density. For this purpose, a special chamber attached to a constant head permeameter was designed and constructed, which allows to measure the permeability in conditions of horizontal flow parallel to the soil layers. The proposed camera also admits the estimation of the permeability coefficient by combining stratifications of different granular soils, where the trajectories are not perfectly horizontal, but have diagonal paths. The results are compared with data obtained by conventional vertical flow permeameters, in order to check the difference in the measurements considering both situations in the samples. As a conclusion, it is important to report that there is evidently a difference in the permeability coefficients measured under different trajectories,

scholarly journals Permeability coefficient tests in non-cohesive soils

2020 ◽  
Vol 29 (1) ◽  
pp. 72-80
Author(s):  
Grzegorz Wrzesiński
Keyword(s):  
Water Table ◽  
Standard Method ◽  
Permeability Coefficient ◽  
Laboratory Tests ◽  
Test Site ◽  
Soil Samples ◽  
Cohesive Soils ◽  
Pumping Tests ◽  
Water Pumping ◽  
Density Index

The paper aims to comparison the permeability coefficient in non-cohesive soils by the method of test pumping and based on tests in a consolidometer. The tests were carried out on 18 types of non-cohesive soils with different fraction. Pumping tests were carried out according to the standard method i.e. by making one well with a diameter of 400 mm and installing two piezometers at different distances from the well. The water table change was measured in piezometers during water pumping from the well. Tests in the consolidometer were carried out on soil samples that were first compacted to the same density index as in the test site. The tests were carried out with a continuous inflow of water from below with constant gradients of 0.50. The tests presented in the paper allow to verify and compare the values of the permeability coefficient in non-cohesive soils determined in the field and laboratory tests.

scholarly journals COMPARISON OF MEASURED AND ESTIMATED PERMEABILITY FOR ARTIFICIALLY PREPARED COARSE-GRAINED SOIL SAMPLES

2021 ◽  
Vol 36 (3) ◽  
pp. 167-178
Author(s):  
Patricia Živković ◽  
Mirela Burečić Šafran ◽  
Biljana Kovačević Zelić
Keyword(s):  
Permeability Coefficient ◽  
Coarse Grained ◽  
Test Fluid ◽  
Soil Permeability ◽  
Empirical Correlations ◽  
Engineering Project ◽  
Field Methods ◽  
Constant Head ◽  
Using Data ◽  
Empirical Coefficients

Knowledge about soil permeability is important in various scientific fields: hydrology and hydrogeology, geotechnics, environmental geotechnics, and others. Depending on the different goals that need to be achieved by a particular engineering project, the conditions in which the permeability coefficient is determined in terms of applied hydraulic gradients, applied stresses, type of test fluid, etc. are adjusted, as well as the required precision of its determination. In addition, the permeability coefficient is a soil property with the largest range of possible values. It can be determined through various laboratory and field methods, and by applying established empirical correlations using data on the grain-size distribution and empirical coefficients that depend on some factors, such as hydraulic radius (specific surface), curvature, porosity, etc. This paper presents the results of laboratory testing of the permeability coefficient by the constant head test and the use of a permeameter. The results were compared with the permeability coefficient obtained by applying a number of empirical correlations. Artificial samples were prepared in the laboratory by mixing different previously prepared soil fractions in order to determine the influence of particle size and soil gradation on the estimated soil permeability coefficient.

scholarly journals Nonlinear stability of two-layer shallow water flows with a free surface

2020 ◽  
Vol 476 (2236) ◽  
pp. 20190594
Author(s):  
Francisco de Melo Viríssimo ◽  
Paul A. Milewski
Keyword(s):  
Free Surface ◽  
Initial Data ◽  
Nonlinear Stability ◽  
Mathematical Proof ◽  
Passive Layer ◽  
Physical Parameters ◽  
Immiscible Fluid ◽  
Dimensional System ◽  
The Cauchy Problem ◽  
The Difference

The problem of two layers of immiscible fluid, bordered above by an unbounded layer of passive fluid and below by a flat bed, is formulated and discussed. The resulting equations are given by a first-order, four-dimensional system of PDEs of mixed-type. The relevant physical parameters in the problem are presented and used to write the equations in a non-dimensional form. The conservation laws for the problem, which are known to be only six, are explicitly written and discussed in both non-Boussinesq and Boussinesq cases. Both dynamics and nonlinear stability of the Cauchy problem are discussed, with focus on the case where the upper unbounded passive layer has zero density, also called the free surface case. We prove that the stability of a solution depends only on two ‘baroclinic’ parameters (the shear and the difference of layer thickness, the former being the most important one) and give a precise criterion for the system to be well-posed. It is also numerically shown that the system is nonlinearly unstable, as hyperbolic initial data evolves into the elliptic region before the formation of shocks. We also discuss the use of simple waves as a tool to bound solutions and preventing a hyperbolic initial data to become elliptic and use this idea to give a mathematical proof for the nonlinear instability.

scholarly journals Technical note: Analytical drawdown solution for steady-state pumping tests in two-dimensional isotropic heterogeneous aquifers

2016 ◽  
Vol 20 (5) ◽  
pp. 1655-1667 ◽  
Author(s):  
Alraune Zech ◽  
Sabine Attinger
Keyword(s):  
Steady State ◽  
Correlation Length ◽  
Heterogeneous Media ◽  
Radial Distance ◽  
Pumping Test ◽  
Two Dimensional ◽  
Aquifer Heterogeneity ◽  
Pumping Tests ◽  
Flow Solution ◽  
Ensemble Mean

Abstract. A new method is presented which allows interpreting steady-state pumping tests in heterogeneous isotropic transmissivity fields. In contrast to mean uniform flow, pumping test drawdowns in heterogeneous media cannot be described by a single effective or equivalent value of hydraulic transmissivity. An effective description of transmissivity is required, being a function of the radial distance to the well and including the parameters of log-transmissivity: mean, variance, and correlation length. Such a model is provided by the upscaling procedure radial coarse graining, which describes the transition of near-well to far-field transmissivity effectively. Based on this approach, an analytical solution for a steady-state pumping test drawdown is deduced. The so-called effective well flow solution is derived for two cases: the ensemble mean of pumping tests and the drawdown within an individual heterogeneous transmissivity field. The analytical form of the solution allows inversely estimating the parameters of aquifer heterogeneity. For comparison with the effective well flow solution, virtual pumping tests are performed and analysed for both cases, the ensemble mean drawdown and pumping tests at individual transmissivity fields. Interpretation of ensemble mean drawdowns showed proof of the upscaling method. The effective well flow solution reproduces the drawdown for two-dimensional pumping tests in heterogeneous media in contrast to Thiem's solution for homogeneous media. Multiple pumping tests conducted at different locations within an individual transmissivity field are analysed, making use of the effective well flow solution to show that all statistical parameters of aquifer heterogeneity can be inferred under field conditions. Thus, the presented method is a promising tool with which to estimate parameters of aquifer heterogeneity, in particular variance and horizontal correlation length of log-transmissivity fields from steady-state pumping test measurements.

scholarly journals A Method and Equipment for Continuously Testing the Permeability Coefficient of Rock and Soil Layers

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Wei Chen ◽  
Datian Cui ◽  
Meng Xu ◽  
Rongchao Xu
Keyword(s):  
Flow Rate ◽  
Test Section ◽  
Permeability Coefficient ◽  
Water Pressure ◽  
Pumping Test ◽  
Testing Method ◽  
Water Pressure Test ◽  
Pressure Test ◽  
Test Hole ◽  
Rock And Soil

The water pressure test and steady-flow pumping test are still commonly used for measuring the permeability coefficient of rock and soil strata. Limited by the fact that the average value of the permeability coefficient could be obtained only by this testing method, the accuracy of the experimental results of the permeability coefficient for special rock and soil strata is not good. Therefore, a new on-site testing method and equipment for continuously measuring the permeability coefficient of rock and soil strata is studied in this paper. The method is suitable for water pressure testing in borehole and the steady-flow pumping test. The technical proposal is when the pumping test or water pressure test is carried out, the final water penetration will tend to be a stable value, and then, the high-precision current meter probe will be placed at the bottom of the pumping test hole or water pressure test hole. For the pumping test, the current meter will be lifted uniformly from the bottom of the borehole testing section to the stable water level. Meanwhile, the flow rate of a differential zone of the tested section is continuously detected. For the water pressure test, the current meter will be lifted uniformly from the bottom of the borehole test section to the top of the borehole test section, and the flow rate of the differential section will be continuously detected. Through data analysis and processing, not only the average permeability coefficient of the detected sections can be obtained but also the permeability coefficient of the differential section of the rock and soil stratum can be calculated, respectively. Furthermore, the corresponding relationship between the permeability coefficient and the detected location can be obtained. In view of the abovementioned reasons, the leaking point, the specific position, and the leakage quantity of the detected section could be found out accurately, which will improve the accuracy of the testing results obviously.

scholarly journals Investigation on Dewatering of a Deep Shaft in Strong Permeable Sandy Pebble Strata on the Bank of the Yellow River

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Yuchao Zheng ◽  
Jianyong Lei ◽  
Fei Wang ◽  
Liang Xiang ◽  
Jianfeng Yang ◽  
...  
Keyword(s):  
Permeability Coefficient ◽  
Yellow River ◽  
Pumping Test ◽  
The Yellow River ◽  
Construction Process ◽  
Deep Excavation ◽  
Ground Settlement ◽  
High Permeability ◽  
Reverse Analysis ◽  
Table Versus

This paper reports the dewatering scheme of a deep excavation in sandy pebble strata. The excavation is in high permeability strata and is close to the Yellow River, making the dewatering difficult during construction. At present, few researchers have specially studied the dewatering scheme of deep excavations in strong permeable strata near the water resource. Field pumping test was conducted before the excavation activity, and the permeability coefficient of the strata was obtained by reverse analysis. According to the characteristics of the project, the dewatering scheme of “ waterproof   curtain + base   grouting + pumping ” was proposed. The influence of vertical waterproof curtain and base grouting on dewatering was analyzed by numerical simulation. In the construction process, the field water table and ground settlement were measured. The results show that (1) the groundwater table versus permeability coefficient curve shows three different stages and (2) the dewatering scheme of “ waterproof   curtain + base   grouting + pumping ” is effective for deep excavation in strong permeable strata.

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