scholarly journals A study of clay soil deformability over time

Vestnik MGSU ◽  
2020 ◽  
pp. 1654-1662
Author(s):  
Marina N. Mikova ◽  
Evgeniya N. Akbulyakova
Keyword(s):  
Clay Soil ◽  
Constant Load ◽  
Clay Soils ◽  
Relative Deformation ◽  
High Plasticity ◽  
Consolidation Process ◽  
Liquidity Index ◽  
Semi Solid ◽  
Very High ◽  
Over Time

Introduction. The study is focused on the process of clay soil deformation over time, provided that this soil, featuring varied liquidity index values, is exposed to constant load. The consolidation process is slow; it can run for years or decades in clay soils. Long-term deformations of clay soils must be taken into account in the course of design and construction of buildings and structures, on the one hand, and in the process of analyzing settlement rates and maximal settlement values for foundation beds, on the other hand. Materials and methods. Semi-solid, low-plasticity, high-plasticity, very high plasticity, and free-flowing clay samples were used in the study. The parameters under research encompass relative and absolute deformation of soil samples over time. These parameters are dependent on the soil liquidity index value. All laboratory tests were carried out in compression machines, and tested samples were exposed to constant load. The experimental data thus obtained were supplemented by the information provided M.A. Koltunov. Results. Values of absolute deformations and time-to-relative deformation ratios were obtained for clays having different liquidity index values. The analysis of the time-to-relative deformation curves shows that deformations develop over time at different rates depending on the liquidity index of clay soils. An increase in the value of the liquidity index boosts the values of initial deformations and deformation rates. Conclusions. The equations, derived in the course of the study, allow to analyze the deformation of semi-solid, low-plasticity, high-plasticity, very high plasticity, and free-flowing clays for various time ranges depending on the initial clay liquidity index. The accuracy of the approximation of these equations varies from 0.801 to 0.993, which makes it possible to characterize these dependences as high quality mathematical models.

scholarly journals PENGARUH PENGGUNAAN KOLOM PASIR, LAYER PASIR, DAN TERUCUK BAMBU PADA TANAH LEMPUNG JENUH AIR TERHADAP PENURUNAN TANAH LEMPUNG MENGGUNAKAN UJI LABORATORIUM

2020 ◽  
Vol 16 (1) ◽  
pp. 64-73
Author(s):  
Dian Eksana Wibowo ◽  
Satriarda Dirgantara S. ◽  
Ridwan Kurniawan
Keyword(s):  
Moisture Content ◽  
Soil Properties ◽  
Water Content ◽  
Clay Soil ◽  
Soil Types ◽  
Soil Conditions ◽  
High Plasticity ◽  
Consolidation Process ◽  
Water Saturated ◽  
Effective Use

ABSTRAKPenelitian ini bertujuan untuk mengetahui klasifikasi jenis tanah, properti tanah pengujian dan pengaruh penggunaan metode penambahan variasi tanah lempung jenuh air dengan menggunakan pasir dan cerucuk bambu, terhadap penurunan tanah lempung, kadar air, dan analisis T90. Penelitian eksperimen dengan menggunakan model boks baja, berukuran 100 cm x 100 cm x 40 cm sebagai media penempatan tanah lempung. Hasil penelitian ini yaitu: (1) Jenis tanah termasuk CH (Clay High Plasticity) menurut klasifikasi USCS dan kelompok 4-7-6(40) menurut klasifikasi AASTHO. (2) Properti tanah adalah G=2,63, LL=74,71%, PL=29,76%, IP=44,95%, SL=19,06%, C=0,75 kg/cm2, OMC=39,2%. (3)  Penambahan TPV sangat efektif memperkecil penurunan. Pada pemberian tekanan 0,0125 kg/cm2, 0,025 kg/cm2, 0,05 kg/cm2, dan 0,01 kg/cm2 memperkecil penurunan, berturut-turut: 75,93%; 56,32%; 59,44% dan 42,32%. Pada kedalaman -10 cm penggunaan TPH paling efektif mengurangi kadar air tanah lempung  yaitu sebesar 53,30%, berarti mengurangi kadar air sebesar 3,62% dari kondisi tanah asli (TTD). Pada kedalaman 20 cm, penggunaan TCB paling efektif mengurangi kadar air sebesar 3,55% dari kadar air tanah lempung asli (TTD). Penggunaan CTPVH pada beban 0,1 kg/cm2 paling efektif dalam proses konsolidasi yaitu sebesar 94,10% dari tanah asli (TTD) dimana mempunyai nilai sebesar nilai t90 untuk CTPVH yaitu sebesar 15,21 menit. Kata Kunci: air, perkuatan, tanah lempung, T90  ABSTRACT This study aims to determine the classification of soil types, soil properties tested and the effect of using the method of adding variations in the water-saturated clay, using sand and bamboo piles, to clay settlement, moisture content, and T90 analysis. The experimental study used a steel box model, measuring 100 cm x 100 cm x 40 cm as a medium for clay placement. The results of this study are: (1) Soil types including CH (Clay High Plasticity) according to USCS classification and groups 4-7-6 (40) according to AASTHO classification. (2) Soil properties is G=2,63, LL=74,71%, PL=29,76%, IP=44,95%, SL=19,06%, C=0,75 kg/cm2, OMC=39,2%. (3) Addition of TPV is very effective in reducing the settlement. At a pressure of 0,0125 kg/cm2, 0,025 kg/cm2, 0,05 kg/cm2, and 0.01 kg/cm2 minimizing the settlement,  respectively: 75,93%; 56,32%; 59,44% and 42,32%. At depths of -10 cm the most effective use of TPH reduces clay soil moisture content by 53,30%, which means reducing water content by 3,62% from the original soil conditions (TTD). At a depth of 20 cm, using TCB is most effective at reducing water content by 3,55% from the original clay soil content (TTD). The use of CTPVH at a load of 0,1 kg/cm2 is most effective in the consolidation process which is 94.10% of the original soil (TTD) which has a value of T90 for CTPVH which is 15,21 minutes. Keywors: water, strainthening, clay, T90

scholarly journals Unidirectional consolidation of clay soils and flocculated suspensions

2021 ◽  
Author(s):  
Stephen Peppin
Keyword(s):  
Diffusion Equation ◽  
Mine Tailings ◽  
Clay Soil ◽  
Convective Diffusion ◽  
Clay Soils ◽  
Stress Profile ◽  
Soil Flow ◽  
Flocculated Suspension ◽  
Convective Diffusion Equation ◽  
Very High

A model of the unidirectional consolidation of a clay soil or flocculated suspension between a series of parallel drains is developed. A convective-diffusion equation for the pore pressure is derived, and an equal-strain approximation leads to an expression for the average effective stress profile between the drains. The solution depends on a Peclet number quantifying the ratio of the bulk soil flow rate to the rate of consolidation. By adjusting the number, height and spacing of the drains, very high rates of dewatering can be achieved. A potential application of the method to the rapid dewatering of mine tailings is described.

scholarly journals A Preliminary Study on the Engineering Properties of Clay Soil

2019 ◽  
Vol 2 (2) ◽  
pp. 39-40
Author(s):  
Mehrin Hoque ◽  
Akhila Palat ◽  
Michael Hendry
Keyword(s):  
Clay Soil ◽  
Saline Water ◽  
Soil Mechanics ◽  
Field Work ◽  
Atterberg Limits ◽  
Engineering Properties ◽  
Clay Soils ◽  
Climate Conditions ◽  
Semi Solid ◽  
Compare And Contrast

Karl Von Terzaghi, the father of soil mechanics, says, “There is no other soil which is as problematic as clay soil”. In many places across the badlands of Alberta, clay soil is known to be troublesome and cause issues with buildings and infrastructure. Climate conditions, erosion and weathering can cause the unstable clay soil to create landslides, which consequently damage many of these structures. For this reason, engineers are sent to these sites to monitor and collect data over a period of time to compare and contrast their results. The purpose of this study is to learn and understand the properties of clay soils through different classification and index tests. Two clay soils, kaolinite and bentonite, were tested for their properties and their results were compared. Some of the tests performed include the hydrometer analysis, pycnometer analysis, and atterberg limits. The hydrometer analysis is the process in determining the size of silts and clays (when sieves cannot be used). The pycnometer analysis is used to determine the specific gravity of a substance. Atterberg limits are used to determine the water content at which a soil starts to shift from liquid, plastic or semi-solid. These tests were done in two different solutions - one containing distilled water and one with saline water - to understand the effect of the solution on the liquid and plastic limits. The goal of this study was achieved and the results can be used to understand more about the engineering properties of clay soils and apply these studies to future field work. By understanding these properties, further research can be done to discover long term solutions to landslides caused by the problematic soil.

Limits to Dominance?

2017 ◽  
Keyword(s):  
Communication Skills ◽  
Electoral System ◽  
Tony Blair ◽  
Prime Ministers ◽  
Margaret Thatcher ◽  
Capital Building ◽  
Low Levels ◽  
Very High ◽  
Over Time ◽  
Policy Vision

This chapter compares the leadership capital of two long-serving UK prime ministers: Tony Blair and Margaret Thatcher, treble election winners who held office for a decade. Mapping their capital over time reveals two very different patterns. Thatcher began with low levels of capital, building to a mid-term high and final fragile dominance, though her capital fell between elections. Blair possessed very high levels from the outset that gradually declined in a more conventional pattern. Both benefited from electoral dominance and a divided opposition, Thatcher’s strength lay in her policy vision while Blair’s stemmed from his popularity and communication skills. The LCI reveals that both prime ministers were successful without being popular, sustained in office by the electoral system. Towards the end of their tenures, both leaders’ continued dominance masked fragility, ousted when unrest in their parties and policy unpopularity eroded their capital.

scholarly journals Influence of Hydrogeochemistry on Tunnel Drainage in Evaporitic Formations: El Regajal Tunnel Case Study (Aranjuez, Spain)

2021 ◽  
Vol 13 (3) ◽  
pp. 1505
Author(s):  
Ignacio Menéndez Pidal ◽  
Jose Antonio Mancebo Piqueras ◽  
Eugenio Sanz Pérez ◽  
Clemente Sáenz Sanz
Keyword(s):  
High Speed ◽  
Civil Engineering ◽  
Saturation Index ◽  
The Subject ◽  
Under Construction ◽  
Underground Flow ◽  
Very High ◽  
Over Time

Many of the large number of underground works constructed or under construction in recent years are in unfavorable terrains facing unusual situations and construction conditions. This is the case of the subject under study in this paper: a tunnel excavated in evaporitic rocks that experienced significant karstification problems very quickly over time. As a result of this situation, the causes that may underlie this rapid karstification are investigated and a novel methodology is presented in civil engineering where the use of saturation indices for the different mineral specimens present has been crucial. The drainage of the rock massif of El Regajal (Madrid-Toledo, Spain, in the Madrid-Valencia high-speed train line) was studied and permitted the in-situ study of the hydrogeochemical evolution of water flow in the Miocene evaporitic materials of the Tajo Basin as a full-scale testing laboratory, that are conforms as a whole, a single aquifer. The work provides a novel methodology based on the calculation of activities through the hydrogeochemical study of water samples in different piezometers, estimating the saturation index of different saline materials and the dissolution capacity of the brine, which is surprisingly very high despite the high electrical conductivity. The circulating brine appears unsaturated with respect to thenardite, mirabilite, epsomite, glauberite, and halite. The alteration of the underground flow and the consequent renewal of the water of the aquifer by the infiltration water of rain and irrigation is the cause of the hydrogeochemical imbalance and the modification of the characteristics of the massif. These modifications include very important loss of material by dissolution, altering the resistance of the terrain and the increase of the porosity. Simultaneously, different expansive and recrystallization processes that decrease the porosity of the massif were identified in the present work. The hydrogeochemical study allows the evolution of these phenomena to be followed over time, and this, in turn, may facilitate the implementation of preventive works in civil engineering.

III. On a new substance occurring in the urine of a patient with mollities ossium

1848 ◽  
Vol 138 ◽  
pp. 55-62 ◽  
Keyword(s):  
Nitric Acid ◽  
Specific Gravity ◽  
Test Tube ◽  
High Specific Gravity ◽  
Solid Substance ◽  
Semi Solid ◽  
Very High

On the 1st of November 1845 I received from Dr. Watson the following note, with a test tube containing a thick, yellow, semi-solid substance:—“The tube contains urine of very high specific gravity; when boiled it becomes highly opake; on the addition of nitric acid it effervesces, assumes a reddish hue, becomes quite clear, but, as it cools, assumes the consistence and appearance which you see: heat reliquifies it. What is it ?” A few hours afterwards a specimen of the same urine, passed by a grocer forty-seven years of age, who had been out of health for thirteen months, was sent to me by Dr. MacIntyre. He being in attendance on the case with Dr. Watson, had two days previously first observed the peculiar reactions of the urine.

Effects of autumn tillage of clay soil on mineral N content, spring cereal yield and soil structure over time

2012 ◽  
Vol 37 (1) ◽  
pp. 96-104 ◽  
Author(s):  
Åsa Myrbeck ◽  
Maria Stenberg ◽  
Johan Arvidsson ◽  
Tomas Rydberg
Keyword(s):  
Soil Structure ◽  
Clay Soil ◽  
Mineral N ◽  
N Content ◽  
Over Time

scholarly journals Effects of High Plasticity and Expansive Clay Stabilization with Lime on UCS Testing in Several Conditions

2021 ◽  
Vol 1000 (1000) ◽  
Author(s):  
Soewignjo Agus Nugroho ◽  
Gunawan Wibisono ◽  
Andarsin Ongko ◽  
Avrilly Zesthree Mauliza
Keyword(s):  
Soil Stabilization ◽  
Soft Soil ◽  
Fine Powder ◽  
High Water ◽  
Liquid Limit ◽  
Clay Soils ◽  
High Water Content ◽  
High Plasticity ◽  
Expansive Clay ◽  
Limit Value

Clay is a cohesive and very soft soil if it has high water content. To overcome this problem, clay soils with high plasticity need to be stabilized. The method of soil stabilization with lime is an alternative effort to improve soil that does not meet the standards. Lime reacts with groundwater so that it changes the property of the soil, reducing the stickiness and softness of the soil. Lime also functions to solidify (stabilize) and stabilize (stabilize) soil in the form of fine powder consisting of metals and inorganic mineral composition. This study aims to determine the effect of clay soils when carried out stabilization by using a limestone additive which varies in levels of mixture. The results showed that lime effective for the stabilization high plasticity and expansive clay by increasing the compressive strength value of UCS with lime content of 10% under curing conditions in 28 days and unsoaked by 319%, the liquid limit value reduced by 6% and the plastic limit value increased by 46%.

scholarly journals Licorice (Glycyrrhiza glabra (Linnaeus, 1753)) roots aqueous extract and some additives against Bactrocera zonata (Saunders, 1841) (Diptera: Tephritidae)

2021 ◽  
Vol 90 (2 - Ahead of print) ◽  
pp. 70-85
Author(s):  
Mervat Abdel-Moneauim Mostafa El-Genaidy ◽  
Mohamed Abd El-Aziz Mohamed Hindy ◽  
Nehad Abdel-Hameed Soliman
Keyword(s):  
Aqueous Extract ◽  
Sandy Soil ◽  
Clay Soil ◽  
Mineral Oil ◽  
Glycyrrhiza Glabra ◽  
Clay Soils ◽  
Insecticidal Effect ◽  
Bactrocera Zonata ◽  
Light Mineral ◽  
Petroleum Oil

Peach fruit fly, Bactrocera zonata (Saunders, 1841) is a destructive polyphagous pest threatening the horticultural production in Egypt. Licorice, Glycyrrhiza glabra (Linnaeus, 1753) is a plant growing in Egypt and many other countries and famous for saponins groups that have insecticidal effect against broad spectrum of insect pests. In the present study, the insecticidal effect of licorice roots aqueous extract (LRAE), petroleum oil, KZ light mineral oil 96% (EC), water and an emulsion (1/4 L LRAE + ¼ L petroleum oil + ½ L KZ light oil 96% (EC)) treatments in a ratio 1 L: 29 L water were used in Matabi® sprayer of 30 L capacity against B. zonata pupae in sandy and clay soils. In sandy and clay soils LRAE reduced B. zonata population by 74.44% and 87.55% while petroleum oil, KZ light mineral oil 96% (EC) prevented flies emergence (100% reduction). Water treatment suppressed B. zonata population by 78.61% in sandy soil but caused 100% population reduction in clay soil. The emulsion reduced B. zonata population by 96.94% in sandy soil and 100% in clay soil. The best method for application of the emulsion was to spray as one target spray technique for eight seconds that was sufficient to obtain suitable coverage on soil with spray speed 1.2 km / hour. The persistence of the emulsion that highly reduced B. zonata larval populations was 3.5 and 4.5 days in sandy and clay soils, respectively. The flies emerged from B. zonata pupae treated with the emulsion neither feed nor move naturally. The histological studies showed that these flies suffered changes in the eyes, labellum, muscles and midgut tissues that were different from the emerged control treatment flies.

scholarly journals An Experimental Study on the Effect of Tire Powder on the Geotechnical Properties of Clay Soils

2018 ◽  
Vol 4 (3) ◽  
pp. 594 ◽  
Author(s):  
Davood Akbarimehr ◽  
Esmael Aflaki
Keyword(s):  
Clay Soil ◽  
Geotechnical Properties ◽  
Atterberg Limits ◽  
Clay Soils ◽  
Positive Effects ◽  
Advantages And Disadvantages ◽  
Different Types ◽  
Problematic Soils ◽  
Geotechnical Problems ◽  
Comprehensive Study

With respect to the increasing production of tire wastes, the use of these wastes as an additive in civil engineering has always gained attentions of researchers due to their positive effects on material properties and reduction of environmental problems. Clay soils, as problematic soils, have always caused geotechnical problems including high Atterberg limits and consequently low workability. Tire powder, as one of the products of tire wastes, lacks clay cohesion and it can be effective in altering the plasticity of clay soils. As no comprehensive study has been conducted in this regard specifically on Tehran clay soil yet, this research studies experimentally the effect of adding different percentages of tire powder to clay soil at the Atterberg limits of clay soils with two different types of plasticity. More over according to previous studies, the effect of tire powder on other geotechnical properties of clay soils and the advantages and disadvantages of using tire powder in clay soils are discussed. The results indicate that addition of tire powder to clay soils has positive effects on reducing the Atterberg limits, increasing efficiency, and improving resistance, permeability, swelling reduction, and settlement properties, and reducing soil density and it can be used as an additive in improving clay soils.

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