INVESTIGATION OF GEOTECHNICAL SPECIFICATIONS OF SAND DUNE SOIL: A CASE STUDY AROUND BAIJI IN IRAQ

ABSTRACT: While more than half the land surface of Iraq consists of deserts covered mainly with sand dunes, little research has taken place to study the characteristics and the behavior of dune soils. This paper directed toward studying the geotechnical properties of dune sands taken from Baiji city (northwest of Iraq). A vast laboratory testing program was carried out to achieve the purpose of this paper. The physical tests, chemical tests, X-ray diffraction analysis, permeability test, compaction characteristics, compressibility and collapsibility tests; and shear strength tests were included in this program. The results indicate that soil of Baiji sand dune exhibits prefer engineering properties according to their state. As such, this soil is considered suitable for use in geotechnical constructions.   ABSTRAK: Walaupun lebih separuh daripada bumi Iraq terdiri daripada gurun yang dipenuhi dengan bukit-bukit pasir, tidak banyak penyelidikan dijalankan untuk mengkaji sifat-sifat dan ciri-ciri tanah pasir  tersebut. Kertas kerja ini menyelidik sifat geoteknikal bukit pasir yang diambil dari pekan Baiji (di bahagian barat utara Iraq).  Program penyelidikan makmal yang menyeluruh telah  dijalankan bagi mencapai objektif kajian ini. Ujian fizikal, ujian kimia, analisis belauan sinar-x, ujian kebolehtelapan, ciri pemadatan, faktor ketermampatan, ujian keruntuhan dan ujian kekuatan ricih diambilkira dalam program ini. Keputusan menunjukkan bahawa tanih bukit pasir Baiji mengutamakan ciri kejuruteraan berdasarkan keadaannya. Oleh itu, tanah ini dianggap sesuai untuk kegunaan pembinaan geoteknikal

INVESTIGATION ON THE USE OF MICROPILES FOR SUBSTITUTION OF DEFECTED PILES BY THE FINITE ELEMENT METHOD

Micropiles are small diameter, cast in – place or grouted piles with steel pipes of (50 to 300 mm) diameters and driven by boring machine. Despite their small wall thickness, high bearing capacity of micropiles provides both axial and pullout resistance.nThis paper is directed to study the behavior of micropiles under static and dynamic loading conditions using the finite element method. The program OpenSees is used in the analysis, it is open – source program, provides information about the software architecture, access to the source code, and the development process. The program is based on the basic commands, which are written in Tcl (pronounced, "tickle"; tool command language). A model for groups of laterally loaded pipe piles in sand was adopted to study the effect of defects on their lateral performance. The geometric arrangement consisted of group series of 2, 4 and 6 equally spaced piles. Eight node brick elements are used to model the pile and the surrounding soil. It was concluded that the deflection of laterally loaded piles decreases when inserting steel micropiles beside the defect pile at two opposite directions. The increase in the group deflection is greater when the defected pile is modeled in the front row

The digital music lab: A big data infrastructure for digital musicology

In musicology and music research generally, the increasing availability of digital music, storage capacities, and computing power enable and require new and intelligent systems. In the transition from traditional to digital musicology, many techniques and tools have been developed for the analysis of individual pieces of music, but large-scale music data that are increasingly becoming available require research methods and systems that work on the collection-level and at scale. Although many relevant algorithms have been developed during the past 15 years of research in Music Information Retrieval, an integrated system that supports large-scale digital musicology research has so far been lacking. In the Digital Music Lab (DML) project, a collaboration among music librarians, musicologists, computer scientists, and human-computer interface specialists, the DML software system has been developed that fills this gap by providing intelligent large-scale music analysis with a user-friendly interactive interface supporting musicologists in their exploration and enquiry. The DML system empowers musicologists by addressing several challenges: distributed processing of audio and other music data, management of the data analysis process and results, remote analysis of data under copyright, logical inference on the extracted information and metadata, and visual web-based interfaces for exploring and querying the music collections. The DML system is scalable and based on SemanticWeb technology and integrates into Linked Data with the vision of a distributed system that enables music research across archives, libraries, and other providers of music data. A first DML system prototype has been set up in collaboration with the British Library and I Like Music Ltd. This system has been used to analyse a diverse corpus of currently 250,000 music tracks. In this article, we describe the DML system requirements, design, architecture, components, and available data sources, explaining their interaction. We report use cases and applications with initial evaluations of the proposed system

SHEAR STRENGTH, COLLAPSIBILITY AND COMPRESSIBILITY CHARACTERISTICS OF COMPACTED BAIJI DUNE SOILS

Baiji city is a vital industrial centre in Iraq since it has the biggest oil refinery. Therefore, Baiji has become an attractive site for strategic construction projects. Dune sand covers about 220 km2 of the area of Baiji city. However, few researches had attempted to study its behaviour. In this study laboratory tests were conducted to determine the shear strength, collapsibility and compressibility of the dune sand at its natural and compacted status. The effect of dry unit weight, moisture content, relative density and soaking on mechanical properties of dune soil was investigated. The results demonstrated that dry and soaked dune specimens tested at their in-situ condition exhibited similar volume changes during shear and identical friction angles. The results of shear tests of both of compacted soaked and unsoaked samples were identical. The collapse potential of dune soil is inversely proportional with the relative density. The minimum axial strain is observed when the samples are compacted to modified effort. The compression index of the compacted specimens is affected by moulding water content, while the rebound index is less sensitive

Effect of Time History on Long-Term Deformation of Gypseous Soils

The time-dependent behavior of three gypseous soils was investigated. The soils had gypsum content of 66%, 44%, and 14.8%. The mineralogical and chemical properties of the soils were determined. Two series of tests were performed. In the first, collapsibility characteristics were investigated for a long period (60 days) by conducting single and double oedometer tests. In the second series, the effect of relative density on collapse with time was investigated. The samples were compacted to 40%, 50%, and 60% relative density and then tested. The results of collapse tests showed that the relationship between the strain and logarithm of effective stress has two vertical lines. The first one represents the collapse settlement taking place within 24 h, while the second one represents the long-term collapse. The collapse potential (CP) in both single and double oedometer tests increases when the gypsum content increases from 14.8% to 66% and when the initial void ratio increases. The CP–logarithm of time relationship for soaked samples prepared at different relative densities under 800 kPa indicated that the CP increased with time for the soil sample compacted at 60% relative density and the increase was higher than those compacted at 40% and 50% relative density. The curves started with a straight line and then a concave downward curve was observed with a high strain. For samples compacted at 40% and 50% relative densities, the curves were interrupted by little soil collapses, while the third curve exhibited smooth relation following the collapse