The behaviour of footings resting on a non-homogeneous soil mass with a crust. Part I. Strip footings

1981 ◽  
Vol 18 (2) ◽  
pp. 250-264 ◽  
Author(s):  
R. K. Rowe ◽  
J. R. Booker
Keyword(s):  
Soil Mass ◽  
Elastic Response ◽  
Soil Parameters ◽  
Wide Range ◽  
Weathered Crust ◽  
Homogeneous Soil ◽  
Finite Layer ◽  
Strip Footings ◽  
Underlying Soil

A convenient and economical finite layer method of analysing the behaviour of footings on a non-homogeneous soil is outlined. This method of analysis is used to investigate the elastic response of strip footings for a wide range of soil profiles involving a weathered crust overlying a main deposit. The stiffness of the crust is considered to be either constant or to decrease with depth while the stiffness of the underlying deposit increases with depth.The effect of layer depth, crust depth, and the rate of variation of stiffness within the crust and the underlying soil are examined. The influence of this non-homogeneity upon settlement profile, differential settlement, and consolidation settlement are discussed and the results obtained from this detailed analysis are compared with results obtained from the approximate use of existing homogeneous elastic solutions.The results of this study are presented in the form of influence charts which may be used in hand calculations to estimate the settlement of footings for a wide range of practical cases. The applicability of the solutions and the determination of soil parameters is briefly discussed.

The behaviour of footings resting on a non-homogeneous soil mass with a crust. Part II. Circular footings

1981 ◽  
Vol 18 (2) ◽  
pp. 265-279 ◽  
Author(s):  
R. K. Rowe ◽  
J. R. Booker
Keyword(s):  
Soil Mass ◽  
Soil Parameters ◽  
Layer Depth ◽  
Worked Example ◽  
Wide Range ◽  
Homogeneous Soil ◽  
Cross Anisotropy ◽  
Strip Footings ◽  
Underlying Soil ◽  
Elastic Soil

The behaviour of circular footings resting on a non-homogeneous elastic soil with a crust is investigated. The stiffness of the crust is assumed to be either constant or to decrease with depth, whereas the stiffness of the underlying soil increases linearly with depth.Consideration is given to the effect of layer depth, crust depth, and the rate of variation of stiffness within the crust and the underlying soil upon the settlement profile. The behaviour of circular footings is then compared with that of strip footings and the relative importance of the crust and the underlying soil parameters is discussed.The influence of cross-anisotropy upon footing response is briefly examined and the effects of neglecting anisotropy are indicated for a number of soil profiles.The results of this study are presented in the form of influence charts which may be used in hand calculations to estimate the settlement of circular footings for a wide range of practical cases. The use of these charts is illustrated by means of a worked example.

scholarly journals Determination of Creep Properties of Clays from VRS Oedometer Tests

2019 ◽  
Vol 38 (2) ◽  
pp. 1857-1871 ◽  
Author(s):  
Tim Tapani Länsivaara
Keyword(s):  
Soft Clay ◽  
Complex Stress ◽  
Soil Parameters ◽  
Rate Variation ◽  
Additional Parameter ◽  
Creep Properties ◽  
Oedometer Test ◽  
Wide Range ◽  
Oedometer Tests

AbstractThe determination of creep properties still relies almost entirely on the incrementally loaded oedometer test introduced about 100 years ago. Although the simplicity of the test assures a robust evaluation of soil parameters, it also introduces some shortcomings like discontinuity of the evaluated parameters and the long duration of the test. In this study, the performance of the variable rate of strain (VRS) oedometer test for determination of creep properties of a sensitive soft clay is studied. The results from a comprehensive test series of VRS oedometer tests on a soft sensitive clay is presented. Three different setups for the strain rate variation were used, and each test was repeated thrice. The tests showed good consistency and yielded equal creep parameters compared to values from traditional incrementally loaded (IL) oedometer tests. The tests further verified that it is possible to describe the complex stress dependency of creep parameters with just one additional parameter to the primary deformation parameters. Compared to the IL tests, the VRS tests offers a faster determination and continuous creep properties for a wide range of stress.

Two-pile interaction factor revisited

2011 ◽  
Vol 48 (5) ◽  
pp. 754-766 ◽  
Author(s):  
S.L. Chen ◽  
C.Y. Song ◽  
L.Z. Chen
Keyword(s):  
Axial Strain ◽  
Pile Group ◽  
Soil Mass ◽  
Soil Parameters ◽  
Pile Head ◽  
Soil System ◽  
Axial Forces ◽  
Interaction Factor ◽  
Wide Range ◽  
Pile Interaction

A rigorous analytical method is developed for calculating the interaction factor between two identical piles subjected to vertical loads. Following the scheme proposed by Muki and Sternberg, the problem is formulated by decomposing the pile soil system into an extended soil mass and two fictitious piles. With the consideration of the compatibility condition that the axial strain of the fictitious pile be equal to the corresponding strain average over the extended soil, a Fredholm integral equation of the second kind governing the unknown axial forces along fictitious piles is established and then solved using numerical procedures. The real pile head settlement is subsequently calculated based on the determined fictitious pile forces and finally, the desired pile interaction factor is derived. Comparison with existing solutions confirms that the conventional interaction factor approach does tend to overestimate the interaction and may cause considerable errors for long compressible piles. Numerical results for the interaction factor between two piles in both semi-infinite and finite layered soils are presented over a wide range of pile and soil parameters, and also the settlement behaviour of a 3 × 3 pile group embedded in a semi-infinite soil is studied by virtue of the newly established interaction factor.

scholarly journals COMPARISON OF TWO METHODS OF SOIL ORGANIC CARBON DETERMINATION

2016 ◽  
Vol 48 (1) ◽  
pp. 47 ◽  
Author(s):  
Gabriela Barančíková ◽  
Jarmila Makovníková
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Statistical Processing ◽  
Soil Samples ◽  
Soil Parameters ◽  
Wide Range ◽  
Soil Complex ◽  
Complex Monitoring ◽  
Carbon Determination

<p>Soil organic carbon (SOC) is one of the basic soil parameters which takes part in many biological, chemical and physical soil processes and the SOC is currently considered as a key indicator of soil quality. For this reason determination of the SOC is a part of soil complex monitoring which has been performed in Slovakia since 1993. From 1993 until 2007 the “wet” method of determination of the SOC was used. Since 2008 the “dry” method for determination of the SOC has been applied. The goal of this work has been to evaluate and compare two methods of the SOC determination; the “wet”(Ťiurin method in modification of Nikitin (TN)) and the “dry” determination of the SOC by means of the CN analyser (EA), which was performed on 95 soil samples of topsoil coming from 17 sampling sites with a wide range of the SOC (1–15%). Sampling sites include arable lands and grasslands and represent main soil types and subtypes of Slovakia. On the basis of statistical processing it has been found that in soils with the SOC content up to 3%, differences between two methods are minimal. However, in the case of a higher content of the SOC, the EA method reaches a higher value than the TN method. Obtained data shows that in the case of soil samples with a higher content of the SOC, when changing an analytical method, the PTF function that reduces differences and allows to use all time series monitoring data should be used for the purpose of the tracking trends of the SOC monitoring.</p><p> </p><p>Celem pracy było porównanie wyników oznaczania węgla organicznego (SOC) w próbkach gleb dwoma metodami: spalania „na mokro“ (Tiurina) oraz spalania „na sucho“ w autoanalizatorzee CN. Analizowano 95 próbek gleb z 17 miejsc kompleksowego monitoringu gleb Słowacji, o zwawartości węgla organicznego od 1 do 15%. Analiza statystyczna wykazała, że różnice wyników oznaczania SOC dwoma metodami w próbkach o zawarości węgla do 3% nie były istotne statystycznie. Dla próbek o wyższej zawartości SOC, wyniki uzyskane metodą spalania „na sucho“ były istotnie wyższe niż uzyskane metodą Tiurina, dlatego do celów porównawczych zawartości SOC w tych glebach oznaczonych różnymi metodami należy stosować odpowiednie przeliczniki.</p>

scholarly journals Salinity–pH Relationships in Calcareous Soils

2003 ◽  
Vol 8 (1) ◽  
pp. 41 ◽  
Author(s):  
A.S. Al-Busaidi ◽  
P. Cookson
Keyword(s):  
Soil Ph ◽  
Soil Salinity ◽  
Negative Relationship ◽  
Calcareous Soils ◽  
Clay Content ◽  
Soil Parameters ◽  
Wide Range ◽  
Agricultural Areas ◽  
The Relationship

Soil pH is the most commonly requested analysis undertaken during farm advisory work. Determination of pH assists in understanding many reactions that occur in soil. Variations in pH between soils have been related to a number of other soil parameters. In this study thirty different soils were collected from agricultural areas to have a wide range of pH, salinity, and texture. The objective was to study the relationship between soil pH and salinity. A negative relationship was found between soil salinity and pH. The main factor contributing to this relationship was probably the presence of soluble Ca2+ ion in soil. Variations in soluble Ca2+ ion concentrations between soils were negatively related to soil pH and positively related to soil salinity. Other soil properties that may affect pH, including CEC, CaCO3, clay content, gypsum and sodium adsorption ratio (SAR), were also determined. 

DINAMIKA POLITIK PERSETUJUAN BERSAMA TENTANG PENETAPAN DESA ADAT DI KABUPATEN ROKAN HULU TAHUN 2014

2017 ◽  
Vol 15 (1) ◽  
pp. 21
Author(s):  
Haryo Suganda ◽  
Raja Muhammad Amin
Keyword(s):  
Regulatory Region ◽  
Field Research ◽  
Analysis Techniques ◽  
Political Dynamics ◽  
Political Interests ◽  
Wide Range ◽  
Information Method ◽  
Qualitative Descriptive ◽  
The Village

This study is motivated the identification of policies issued by the regional Governmentof Rokan Hulu in the form of Regulatory region number 1 by 2015 on the determination of thevillage and Indigenous Village. Political dynamics based on various interests against themanufacture of, and decision-making in the process of formation of the corresponding localregulations determination of Indigenous Villages in the Rokan Hulu is impacted to a verysignificantamount of changes from the initial draft of the number i.e. 21 (twenty one) the villagebecame Customary 89 (eighty-nine) the Indigenous Villages who have passed. Type of thisresearch is a qualitative descriptive data analysis techniques. The research aims to describe theState of the real situation in a systematic and accurate fact analysis unit or related research, aswell as observations of the field based on the data (information). Method of data collectionwas done with interviews, documentation, and observations through fieldwork (field research).The results of the research on the process of discussion of the draft local regulations andmutual agreement about Designation of Indigenous Villages in the Rokan Hulu is, showed thatthe political dynamics that occur due to the presence of various political interests, rejectionorally by Villagers who were judged to have met the requirements of Draft Regulations to beformulated and the area for the set to be Indigenous Villages, and also there is a desire fromsome villages in the yet to Draft local regulations in order to set the Indigenous village , there isa wide range of interests of these aspects influenced the agreement to assign the entire localVillage which is in the Rokan Hulu become Indigenous village, and the village of Transmigrationinto administrative Villages where the initiator of the changes in the number of IndigenousVillages in the Rokan Hulu it is the desire of the local Government of its own.

scholarly journals Recent Developments in the Determination of Biomarkers of Tobacco Smoke Exposure in Biological Specimens: A Review

2021 ◽  
Vol 18 (4) ◽  
pp. 1768
Author(s):  
Hernâni Marques ◽  
Pedro Cruz-Vicente ◽  
Tiago Rosado ◽  
Mário Barroso ◽  
Luís A. Passarinha ◽  
...  
Keyword(s):  
Tobacco Smoke ◽  
Solid Phase ◽  
Smoke Exposure ◽  
Tobacco Smoke Exposure ◽  
World Health ◽  
Second Hand Smoke ◽  
Tobacco Exposure ◽  
Wide Range ◽  
Recent Developments

Environmental tobacco smoke exposure (ETS) and smoking have been described as the most prevalent factors in the development of certain diseases worldwide. According to the World Health Organization, more than 8 million people die every year due to exposure to tobacco, around 7 million due to direct ETS and the remaining due to exposure to second-hand smoke. Both active and second-hand exposure can be measured and controlled using specific biomarkers of tobacco and its derivatives, allowing the development of more efficient public health policies. Exposure to these compounds can be measured using different methods (involving for instance liquid- or gas-chromatographic procedures) in a wide range of biological specimens to estimate the type and degree of tobacco exposure. In recent years, a lot of research has been carried out using different extraction methods and different analytical equipment; this way, liquid–liquid extraction, solid-phase extraction or even miniaturized procedures have been used, followed by chromatographic analysis coupled mainly to mass spectrometric detection. Through this type of methodologies, second-hand smokers can be distinguished from active smokers, and this is also valid for e-cigarettes and vapers, among others, using their specific biomarkers. This review will focus on recent developments in the determination of tobacco smoke biomarkers, including nicotine and other tobacco alkaloids, specific nitrosamines, polycyclic aromatic hydrocarbons, etc. The methods for their detection will be discussed in detail, as well as the potential use of threshold values to distinguish between types of exposure.

scholarly journals Applicability of Cork as Novel Modifiers to Develop Electrochemical Sensor for Caffeine Determination

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 37
Author(s):  
Mayra K. S. Monteiro ◽  
Djalma R. Da Silva ◽  
Marco A. Quiroz ◽  
Vítor J. P. Vilar ◽  
Carlos A. Martínez-Huitle ◽  
...  
Keyword(s):  
Electrochemical Sensor ◽  
Linear Response ◽  
High Performance ◽  
Low Cost ◽  
Pharmaceutical Formulations ◽  
Caffeine Concentration ◽  
Real Samples ◽  
Wide Range ◽  
Potential Use

This study aims to investigate the applicability of a hybrid electrochemical sensor composed of cork and graphite (Gr) for detecting caffeine in aqueous solutions. Raw cork (RAC) and regranulated cork (RGC, obtained by thermal treatment of RAC with steam at 380 °C) were tested as modifiers. The results clearly showed that the cork-graphite sensors, GrRAC and GrRGC, exhibited a linear response over a wide range of caffeine concentration (5–1000 µM), with R2 of 0.99 and 0.98, respectively. The limits of detection (LOD), estimated at 2.9 and 6.1 µM for GrRAC and GrRGC, suggest greater sensitivity and reproducibility than the unmodified conventional graphite sensor. The low-cost cork-graphite sensors were successfully applied in the determination of caffeine in soft drinks and pharmaceutical formulations, presenting well-defined current signals when analyzing real samples. When comparing electrochemical determinations and high performance liquid chromatography measurements, no significant differences were observed (mean accuracy 3.0%), highlighting the potential use of these sensors to determine caffeine in different samples.

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