scholarly journals Effect of Pile Spacing on Group Efficiency in Gypseous Soil

2019 ◽  
Vol 5 (2) ◽  
pp. 373 ◽  
Author(s):  
Bilal Jabbar Noman ◽  
Safaa H. Abd-Awn ◽  
Hassan O. Abbas
Keyword(s):  
Bearing Capacity ◽  
Load Condition ◽  
Soil Mass ◽  
Deep Foundation ◽  
Collapsible Soil ◽  
Floating Pile ◽  
Group Efficiency ◽  
Gypsum Content ◽  
Group Pile ◽  
Gypseous Soil

As a matter of fact, the gypseous soil is usually considered as collapsible soil, such type of soil illustrates high resistance to settlement and high bearing capacity when it is dry, but it loses these characteristics when it is inundated and collapses excessively because of the sudden decrease in the volume of the surrounding soil mass. It is founded in the arid and semi-arid regions of the world in Asia, South Asia (Iraq, Syria, Jordan, Yemen, and Iran), North Africa, North America, moreover, it covers more than (31%) of the surface area in Iraq. Gypseous soil is one of the most difficult problems facing the process of building any project because of the difficulty of preventing leakage of water to the soil in practice. Deep foundation (piles) are one of the most common types used in collapsible soils which penetrating problematic soil layers and reaching more hard ones (end bearing piles) or transfers loads depending on skin friction (floating pile). The current work is directed to study the behavior of single and group driven pile of square pattern (4 piles) in case of floating pile (friction pile) with different spacing (2D, 4D, 6D) and length to diameter (L/D) ratio of (20) in this special medium dense soil (gypsum content 30% and 61%) under axial load condition. The investigation was carried out to measure the soil collapse before and after inundation. The results showed that the group efficiency for spacing 2D is less than one while for spacing 4D and 6D are more than that value. In addition, the spacing 4D was more efficient to carry 4 group pile in both dry and soaked cases, in addition, the result showed a high reduction in the bearing capacity at inundation state of group pile of (82% in gypsum content 30%) and ( 87% in gypsum content 61%) with respect to dry state.

scholarly journals Dynamic Response of Single Pile Subjected to Different Frequencies in Gypseous Soil

2020 ◽  
Vol 13 (4) ◽  
pp. 50-57
Author(s):  
Noor D. Abd ◽  
Safa H. AbidAwn
Keyword(s):  
Experimental Study ◽  
Dynamic Response ◽  
Slenderness Ratio ◽  
Vibration Source ◽  
Single Pile ◽  
Collapsible Soil ◽  
Dynamic Movement ◽  
Steel Container ◽  
Gypsum Content ◽  
Gypseous Soil

This paper exhibits an experimental study on dynamic response of a single pile under dynamic load which comes from motor placed on cap pile called a vibration source. This study used the effect of the dynamic movement of vibration on one pile, collapsible soil (gypseous soil) used in this study with 30% gypsum content. The experiment is performed in a dry and soak state. A solid steel pile with a slenderness ratio of 27 was inserted into the soil after preparing it in layers in a steel container (30 * 30 * 60) cm. The test was performed under a dynamic response to the different frequencies 10, 15, 20, and 25 Hz. The results showed that the speed, acceleration and displacement increase with increasing frequency of the vibration source in addition to that the values of speed, acceleration and displacement amplitude are less in the case of soaking compared to their values in the dry state.

Influence of Acetic Acid on Gypseous Soil

2020 ◽  
Vol 1002 ◽  
pp. 511-519
Author(s):  
Lamyaa Najah Snodi ◽  
Israa Saleh Hussein
Keyword(s):  
Acetic Acid ◽  
Soil Mass ◽  
Test Results ◽  
Shear Strength Parameters ◽  
Steel Cylinder ◽  
Soaking Time ◽  
Gypsum Content ◽  
Thick Steel ◽  
Laboratory Models ◽  
Gypseous Soil

Gypseous soil disturbed in many regions in the world. Existence of this soil with high gypsum content caused many damages to the buildings and structures that built on it due to dissolve and leaching of the gypsum slates by the flow of water through the soil mass. Therefore, it is necessary to study the properties of such soil. The dissolve of gypsum depends on many factors such as (gypsum content, temperature and other factors). Another important factor which is the acidity of the dissolution liquid must be considered. This study observes the influence of Acetic acid (CH3COOH) on the gypseous soil. Laboratory models includes (270 mm diameter) and (500 mm height) thick steel cylinder container and 17.1 kN/m3 density gypseous soil compacted in three layers, with gypsum content about 58% . The relation between the soaking time and the shear strength parameters was investigated. Also, plastic square container dimensions (250 mm x 250 mm x 300mm) used with same conditions to observed the deformation of the soil. The aim of this study is to simulate the infiltration of Acid in Gypseous soil. Test results show that increase cohesion of soil for diluted acid while decrease cohesion values for concentrated acid. Angle of friction for soil was increase for diluted and concentrated acid.

Effect of Cavities from Gypsum Dissolution on Bearing Capacity of Soil under Square Footing

2020 ◽  
Vol 857 ◽  
pp. 221-227
Author(s):  
Israa Saleh Hussein ◽  
Lamyaa Najah Snodi
Keyword(s):  
Bearing Capacity ◽  
Water Flow ◽  
Three Dimensional ◽  
Cavity Volume ◽  
Finite Element Program ◽  
Square Footing ◽  
Gypsum Content ◽  
Element Program ◽  
Three Dimensional Finite Element ◽  
Gypseous Soil

This study deals with cavities under square footing which resulted from gypsum dissolving due to water flow in gypseous soil. This process leads to collapse of soil structure and progressive compression. A model was developed for governing the mass-transport to assess the variation of gypsum content of the soil during dissolution by ground water flow then cavity formation was adopted. A general three-dimensional finite element program (PLAXIS 3D) was selected for numerical analysis method to generate the solution. The study included a number of variables and their effect on bearing capacity of gypseous soil such as (gypsum content, cavity volume and location). The cavity was represented as axis and plane cavity which has square section. The results show that the most dangerous case is found when the cavity locates at the center of footing base (Z/B = 0), where the bearing capacity decreased by (14, 37, and 69%) for (20, 30, and 40%) gypsum dissolving ratio respectively. Also, the bearing capacity decreased when the cavity volume increases due to increasing dissolution ratio. The effect of cavity became disappear after (Z/B = 4). While, when using plane cavity, there was no cavity at center of footing base (Z/B = 0) because it considered as a hole not cavity. When using plane cavity, the bearing capacity decreased by (28, 43, and 53%) for (20, 30, and 40%) dissolving ratio respectively when (Z/B=1). The effect of cavity on the bearing capacity would be disappear as the distance from footing center increase until it became disappear at (Z/B = 6 m). The plane cavity is more dangerous than axis cavity.

Variation of Matric Suction as a Function of Gypseous Soil Dry Density

2020 ◽  
Vol 38 (6A) ◽  
pp. 861-868
Author(s):  
Hussein H. Karim ◽  
Qasim A. Al-Obaidi ◽  
Ali A. Alshamoosi
Keyword(s):  
Water Content ◽  
Time Domain ◽  
Deformation Behaviour ◽  
Soil Mass ◽  
Matric Suction ◽  
Time Domain Reflectometry ◽  
Dry Density ◽  
Data Logger ◽  
Collapsible Soil ◽  
Gypseous Soil

Gypseous soil is one of the most problematic types of collapsible soils which is affected by many geotechnical factors. The most important factors are the effect of loading and wetting and their relation to soil density, especially when the soil at unsaturation condition. Suction pressure is the main criteria in determining the deformation behaviour of unsaturated collapsible soil when these soils distributed in arid or semi-arid region. In this study, disturbed sample of sandy soil of more than 70% gypsum content is taken from Al-Ramadi city western of Iraq. This study interested to investigate the variation of matric suction with the dry density and their effects on deformation of gypseous soil. For this purpose, a soil-model device provided with high accurate Tensiometers and Time Domain Reflectometry sensors in addition to data logger is designed and manufactured. Tensiometer sensor is used to monitor and measure the matric suction, while the Time Domain Reflectometry is used to monitor and measure the volumetric water content in the soil mass. The results of the tests showed that there is a significant effect of soil dry density on the relationship between the matric suction and water content.

scholarly journals Improving Gypseous Soil Properties by Using Non-Traditional Additives

2019 ◽  
Vol 12 (4) ◽  
pp. 207-213
Author(s):  
Dhay Waddy Mohammed ◽  
Balqeea A. Ahmed ◽  
Maysam Th. AL-Hadidi
Keyword(s):  
Experimental Work ◽  
Soil Mass ◽  
Polymer Materials ◽  
Engineering Properties ◽  
Untreated Soil ◽  
Gypsum Content ◽  
The World ◽  
Noticeable Improvement ◽  
Flow Through ◽  
Gypseous Soil

Gypseous soils are common in several regions in the world including Iraq, where more than 28.6% of its surface is covered with this type of soil. This soil, with high gypsum content, causes different problems for construction and strategic projects. As a result of water flow through the soil mass, the permeability and chemical arrangement of these soils varies with time due to the solubility and leaching of gypsum. In this study, the soil of 36% gypsum content, was taken from one location about 100 km southwest of Baghdad, where the samples were taken from depths (0.5 - 1) m below the natural ground and mixed with (3%, 6%, 9%) of Copolymer and Novolac polymer to improve the engineering properties that include: collapsibility, permeability and compaction parameter. Results of experimental work showed noticeable improvement of collapsibility and permeability for the soil treated with polymer materials compared to untreated soil. Adding 3% of polymer (copolymer and novolac polymer) materials gave the best improvement in collapsibility which reached to (44.5 and 46%), respectively, in 3 hours. The improvement in permeability reached to 98.6% copolymer and 86.2% novolac polymer in 1 day.

scholarly journals The Bearing Capacity of a Group-Pile Foundation with Inclined Piles under Lateral Loading.

2002 ◽  
pp. 97-107 ◽  
Author(s):  
Makoto KIMURA ◽  
Hiroshi MAKING ◽  
Katsunori OKAWA ◽  
Hiroyuki KAMEI ◽  
Feng ZHANG
Keyword(s):  
Bearing Capacity ◽  
Pile Foundation ◽  
Lateral Loading ◽  
Group Pile

scholarly journals The Interaction Features of the Multi-Level Retaining Walls with Soil Mass

2017 ◽  
Vol 26 (3) ◽  
pp. 179-190
Author(s):  
Igor Boyko ◽  
Liudmyla Skochko ◽  
Veronica Zhuk
Keyword(s):  
Numerical Modelling ◽  
Numerical Simulations ◽  
Variable Stiffness ◽  
Retaining Walls ◽  
Soil Mass ◽  
Soil Base ◽  
Deep Foundation ◽  
Multi Level ◽  
Horizontal Displacements

Abstract The interaction features of multi-level retaining walls with soil base were researched by changing their geometric parameters and locality at the plan. During excavation of deep foundation pits it is important to choose the type of constructions which influences on the horizontal displacements. The distance between the levels of retaining walls should be based on the results of numerical modelling. The objective of this paper is to present a comparison between the data of numerical simulations and the results of the in-situ lateral tests of couple piles. The problems have been solved by using the following soil models: Coulomb-Mohr model; model, which is based on the dilatation theory; elastic-plastic model with variable stiffness parameters.

scholarly journals Experimental Pullout Capacity of Screw Piles in Dry Gypseous Soil

2021 ◽  
Vol 318 ◽  
pp. 01002
Author(s):  
Mahdi O. Karkush ◽  
Omar J. Mukhlef
Keyword(s):  
Relative Density ◽  
Offshore Structures ◽  
Pullout Capacity ◽  
Single Screw ◽  
Gypsum Content ◽  
Pullout Testing ◽  
D 20 ◽  
Pile Model ◽  
Supporting Structures ◽  
Gypseous Soil

Screw piles are widely used in supporting structures subjected to pullout forces, such as power towers and offshore structures, and this research investigates their performance in gypseous soil of medium relative density. The bearing capacity and displacement of a single screw pile model inserted in gypseous soil with various diameters (D = 20, 30, and 40) mm are examined in this study. The soil used in the testing had a gypsum content of 40% and the bedding soil had a relative density of 40%. To simulate the pullout testing in the lab, a physical model was manufactured with specific dimensions. Three steel screw piles with helix diameters of 20, 30, and 40 mm are used, with a total length of 500 mm. The helix is continuous over the pile's embedded depth of 400 mm. The results of tests revealed that decreasing the length to diameter (H/D) ratio resulted in a higher pullout capacity of screw piles and a lower corresponding displacement.

scholarly journals A model for ultimate bearing capacity of piles in unsaturated soils under elevated temperatures

2020 ◽  
Vol 205 ◽  
pp. 05003
Author(s):  
Sannith Kumar Thota ◽  
Farshid Vahedifard
Keyword(s):  
Bearing Capacity ◽  
Unsaturated Soils ◽  
Elevated Temperatures ◽  
Skin Resistance ◽  
Ultimate Bearing Capacity ◽  
Temperature Dependent ◽  
Deep Foundation ◽  
Energy Applications ◽  
Temperature Dependent Model ◽  
Pile Resistance

Geo-energy applications such as energy piles can expose unsaturated, deep foundation soils to elevated temperatures. This paper presents a closed-form equation for the ultimate bearing capacity of piles in unsaturated soils subject to elevated temperatures under drained conditions. For this purpose, a temperature-dependent effective stress model was incorporated into calculations of skin resistance and end bearing resistance of piles. The proposed temperature-dependent model is an extension of the modified β method for determining the ultimate pile bearing capacity of unsaturated soils under drained conditions. Employing the proposed model, a parametric study was carried out to evaluate the ultimate pile bearing capacity for hypothetical clay and silt soils at temperatures ranging from 25 °C to 55 °C. For both clay and silt, the results indicated that the ultimate pile bearing capacity varies with an increase in temperature. Different trends with temperature were observed for clay and silt. A monotonic increase in pile resistance was observed in clays. For silt, the pile resistance increased at relatively low matric suction whereas it decreased at higher matric suctions.

scholarly journals REVIEW OF BEARING CAPACITY AND SETTLEMENT OF PILE FOUNDATION IN PORT INFRASTRUCTURE

Pondasi ◽  
2020 ◽  
Vol 23 (2) ◽  
pp. 1
Author(s):  
Adi Sunarno ◽  
Rinda Karlinasari ◽  
Abdul Rochim
Keyword(s):  
Bearing Capacity ◽  
Pile Foundation ◽  
Pile Group ◽  
Standard Penetration Test ◽  
Infrastructure Development ◽  
Lateral Deflection ◽  
Economic Progress ◽  
Port Infrastructure ◽  
Pile Length ◽  
Group Pile

ABSTRACTThe rapid infrastructure development is one of the indicators on the country economic progress. Indonesia as one of the largest archipelagic countries in the world, should be prioritized the port infrastructure to support the maritime. One of the government’s solutions is infrastructure development of Kuala Tanjung port. This research analyzed bearing capacity and settlement of single and group pile foundation on port infrastructure of Kuala Tanjung so it is known that the port is safe to use. The data used are Standard Penetration Test data with soil stratigraphy that is clay and sand. The type of foundation used is Concrete Spun Pile 1000 mm and 600 mm with a pile length of 36 meters. The data are then analyzed by manual calculation and Allpile 6.5E program based on Reese method and methods such as Vesic and Converse-Labarre. The results showed that single pile foundations of 1000 mm and 600 mm each had allowable capacity (Qall) 492.78-538.81 ton and 110.65-128.31 ton, with vertical load (Q) of 330.90 ton, settlement 0.56-1.17 cm and 3.32-3.64 cm, lateral deflection 27.50 cm and 94.90 cm. While the 1000 mm and 600 mm pile group foundations respectively have Qall 8717.31-10796.29 tons and 2059.25-2566.32 tons, with Q of 6618 tons, settlement 0.56-1.68 cm and 3.32-3.64 cm, lateral deflection of 2.49 cm and 19.49 cm. The conclusion of the research indicates that the safe pile foundation used is 1000 mm group pile foundation. Keywords: Bearing Capacity; Foundations; Pile Foundation; Port Infrastructure; Settlement

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