Articles

  1. DURABILITY OF EXPANSIVE SOIL USING ADVANCED NANOCOMPOSITE STABILIZATION Download Article

    Waseim Ragab Azzam
    • Article Type: Research Article
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    • Pages (927-937)
    • No of Download = 694

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    This article describes the effect of creating nanocomposite materials on the long-term durability of expansive soil. A series of tests were performed to examine the effect of induced nanocomposites on the durability behaviors of the expansive clay. Tests were carried out at different polymer contents and curing time. The nano-structure was examined to confirm the occurrence of nanocomposites through the stabilized samples. The results showed that the curing time can be modified the consistency state of stabilized samples. The induced nanocomposites within the swelling clay can be attributed to non-plastic properties and acted as a hydraulic binder with lesser swelling potential. After long term curing time 28 days, the use of 15% polymer content reduced the swell percent by 90% and increased the stiffness by 4.5 time of its initial value. The improving factor in its unconfined strength was found to be 220%. This can be tended to improve the long term durability and increased the resistance to immersion which confirmed the produced durable hydrophobic material.

  2. GEOCHEMISTRY OF PALEOGENE RED BEDS IN THE NORTHERN IRAQ FORELAND BASIN: EVIDENCE FOR PROVENANCE Download Article

    Muatasam Hassan, Brian G. Jones, Ali Ismail Al Jubory, Sabah Ahmed Ismail, Abdual Salalm Mehdi Saleh and Fahad Mubarak Al Gahtani
    • Article Type: Research Article
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    • Pages (938-944)
    • No of Download = 938

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    The Paleogene Red Bed deposits in northern Iraq crop out as a narrow northwest-southeast trending belt within the thrust zone in an active foreland basin developed adjacent to the Zagraos orogenic belt. The Red Beds are divided vertically into four units. The lower part (unit 1) is mainly composed of red mudstone and siltstone. The middle part (unit 2) is mainly composed of sandstone with thin interbeds of red siltstone. The upper part is composed of conglomerate (unit 3) covered by 100-120 m of red mudstone, siltstone and sandstone (unit 4). The geochemical stratigraphy shows an increase in transition elements and REEs while LILE and HFSE elements decrease in the lower part of the sequence. These features indicate that a mafic source supplied detritus during the deposition of the lower Red Beds and decreased in importance during the deposition of the middle and upper parts as a result of erosion or tectonic activity.

  3. UNIFIED FINITE ELEMENT MODEL FOR SWELLING AND SHRINKAGE BEHAVIOUR OF EXPANSIVE SOILS Download Article

    Hussein Elarabi
    • Article Type: Research Article
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    • Pages (945-949)
    • No of Download = 533

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    The mechanical behaviour of soil is quite complicated and depends on many factors. Expansive soils are those clayey materials which exhibit significant volume changes caused by changes in the subsoil moisture. This has been a subject of research for many years, and the advent of the numerical technique of finite element has given added impetus to these effects. A constitutive law is developed and implemented in a finite element program. The finite element technique is used to compute displacements and stresses developed in structures and soil along time of activity of the swelling. The main objective of this work is to verify the produced unified model for the swelling and shrinkage behaviour of expansive soil. To see the performance of the soil in dryness process, the computation of the heave and stress is continued after the assumed time of wetting period. The values of the heave of soil reduce after reaching a peak value. The reductions of the values of heave are different from layer to layer depending on the rate of loss of water. The main conclusions driven from the various aspects of this study are consistent with the literature findings.

  4. STRENGTH PARAMETER SELECTION IN STABILITY ANALYSIS OF RESIDUAL SOIL NAILED WALLS Download Article

    Atefeh Asoudeh and Erwin Oh
    • Article Type: Research Article
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    • Pages (950-954)
    • No of Download = 1559

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    This paper investigates slope stability of soil nailed walls which are located on sites formed with mostly residual soils. Residual soils, forming from weathered rocks can be found in many parts of the world with different characteristics and appearance based on type of the parent rock they have been formed of. A review on geotechnical properties of residual soils that have been used in previous studies in different parts of the world will be presented and then evaluated to be used as parameters for numerical analysis of soil nailed walls. Slope stability assessment is performed by LEM analysis and a discussion on the results of analysis is presented in this paper.

  5. A STUDY OF THE PARAMETERS AFFECTING THE PERFORMANCE OF ROADS UNDER AN EXTREME RAINFALL EVENT Download Article

    Helen Fairweather and John Yeaman
    • Article Type: Research Article
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    • Pages (955-960)
    • No of Download = 548

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    Sunshine Coast Regional Council has recently upgraded a section of Sippy Downs Drive adjacent to the University of the Sunshine Coast campus. Prior to opening, the pavement was instrumented to monitor strain and moisture in the surface and the subgrade layers and the temperature under the surface layer. At the time of installation, traffic was light, as University classes had not yet commenced. Traffic increased when classes commenced in February 2013 and is projected to grow substantially as a new suburb and two major shopping centres are built over the next three years. Data are recorded every minute and downloaded by mobile phone connection every 24 hours. These data are analysed automatically every day. Six weeks after opening, a major rainfall event occurred with nearly 500mm of rain recorded over three days. The paper discusses the impact on pavement strain as a function of changing moisture content and temperatures. These data have potential for identifying future maintenance requirements.

  6. APPLICATION OF MICROTREMOR MEASUREMENT FOR ESTIMATE OF OVERALL STIFFNESS OF LEVEES Download Article

    Atsushi Mikami
    • Article Type: Research Article
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    • Pages (961-968)
    • No of Download = 1841

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    This study explores the feasibility of estimating overall shear wave velocity for levees to detect weak sections by using microtremor measurement. Microtremor measurement is carried out on the crest and near the toe of the levee embankment simultaneously by placing servo-type velocity sensors perpendicular to the levee axis. Then, transfer functions are calculated using the horizontal motions. Finally, overall shear wave velocity structure is identified so that the peak frequency of the transfer function and the fundamental frequency of finite element model of the levee that has the same cross section coincide. The identified shear wave velocities are mostly consistent with shear wave velocities estimated based on SPT blow counts. Hence, this method is feasible to detect weak sections along levees.

  7. INTERACTION MECHANISMS OF SOIL-GEOSYNTHETIC REINFORCEMENT Download Article

    Mabrouk Touahmia
    • Article Type: Research Article
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    • Pages (969-973)
    • No of Download = 979

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    The pullout performance of geosynthetic reinforcements under static and sustained loading is described in this paper. Laboratory tests were conducted to investigate the cumulative effects of loading on the pullout capacity and behaviour of geogrid reinforcements. The test methods and procedures for analyzing and interpreting the data are presented. The mechanics of load transfer and reinforcement displacement are also examined. In general, the results showed that under static loading applications the geogrid experienced a gradual deformation with load increase. No peak load was observed with the system of loading used and the deformation of the geogrid was mainly close to the point of load application. The sustained loading tests showed no cessation of creep displacement of the geogrid throughout the testing periods of this investigation.

  8. STRESS - STRAIN BEHAVIOUR OF SLAG CEMENT CONCRETE Download Article

    Mustapha Boukendakdji
    • Article Type: Research Article
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    • Pages (974-979)
    • No of Download = 1031

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    The paper describes the results of test carried out on OPC concrete and slag cement concretes. Ten blended slag-cement concretes, made with typical slags from four countries (United Kingdom, Belgium, South Africa and Japan), are compared with a control OPC concrete. The slags replaced 30 to 70% of cement by mass. The bobbin shaped specimens were used in the direct tension test and 300x150 mm dia. cylindrical specimens were used in the axial and lateral strain tests. Poisson's ratio in compression was determined as the ratio of the lateral to axial strain at the ages of 14 and 84 days. Concretes at the age 84 days exhibits more linearity than at the age of 14 days and slag concrete becomes more brittle when stored in the dry environment. There was no difference between the Poisson's ratio of slag and OPC concretes.

  9. EMPIRICAL CORRELATION OF SHEAR WAVE VELOCITY AND N-SPT VALUE FOR JAKARTA Download Article

    Achmad Fauzi, Masyhur Irsyam and Usama Juniansyah Fauzi
    • Article Type: Research Article
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    • Pages (980-984)
    • No of Download = 844

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    This paper proposes an equation representing shear wave velocity (Vs) as a function of SPT blow count (N-SPT). The equation is generated by statistical regression of site investigation data at many building project in Jakarta. The N-SPT values and Vs values were obtained from the same boreholes between 2005 and 2012. The Vs values were obtained by the downhole seismic survey. A total of 22 building and 35 borings provided 234 pairs of N-SPT and Vs values were used to get a regression equation. The new and previously suggested formulae have been compared and evaluated by using the same dataset. Wave propagation analysis require Vs as an input parameter, and the empirical equation may be useful for estimating Vs at site where only N-SPT data available. The information of empirical correlation can and perhaps should be considered in developing microzonation map of Jakarta as inputs in a continuous process of risk assessment and disaster mitigation risk reduction.

  10. EFFECT OF THE MOLAR RATIO OF LIQUID GLASS GROUTING AGENTS ON MECHANICAL CHARACTERISTICS OF THE SOLIDIFIED SOILS Download Article

    Shinya Inazumi, Hsin Ming Shang, Suttisak Soralump, Yoshihiro Nakagishi, Yoshio Miyatani, Yuji Mori and Yu Okuno
    • Article Type: Research Article
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    • Pages (985-992)
    • No of Download = 1137

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    Chemical grouting techniques are used as ground improvement methods to obtain stable ground. In this method, soft sandy soils are solidified by injecting liquid solidification agents into the soils to prevent liquefaction as well as to increase strength. In this study, liquid glass grouting agents containing liquid glass with a higher polymerization degree (No. 5 liquid glass grouting agents) are being developed and discussed while focusing on the liquid agents to be used for chemical grouting techniques. Specifically, the solidification properties of No. 5 liquid glass grouting agents and the influence of the molar ratio of liquid glass to the strength and shrinkage characteristics of sand-gel and homo-gel are experimentally studied. As a result, the sand-gel made of No. 5 liquid glass grouting agents is superior in strength and has smaller shrinkage ratios after gelation, and therefore, is superior in soil improvement.

  11. EXPERIMENTAL AND PREDICTIVE MECHANICAL STRENGTH OF FIBER REINFORCED CEMENTITIOUS MATRIX (FRCM) Download Article

    P.B. Sakthivel, A. Ravichandran and N. Alagumurthi
    • Article Type: Research Article
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    • Pages (993-1002)
    • No of Download = 1085

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    Fiber Reinforced Cementitious Matrix (FRCM) are sustainable building materials as it uses lesser quantities of natural resources as raw materials for production, when compared to conventional concrete. This study is an attempt to explore the possibility of using crimped mild steel (MS) fibers (12.5 mm length) as reinforcement in cementitious matrix, with sand-cement and water-cement ratio in line with the ACI Codes. From the experimental results, it was found that when the percentage of MS fibers is increased in cement-based mortar from 0.5% to 2.5% of volume of specimens (with 0.5% interval), there is a corresponding increase in the cylinder compressive strength and splitting-tensile strength at 7 and 28 days, and flexural strength at 28 days. There was an increase in compressive strength of 74%, splitting-tensile strength of 38% and flexural strength of 35% at 28 days, when MS fibers of 2.5% was used, when compared to control mortar specimens (with no fibers). Also, the predictive strength models were developed from the experimental data using statistical regression analysis. It was observed that the experimental results of FRCM highly correlate with the predicted values, with minimum prediction error.

  12. EFFECTIVENESS OF CRASHED TILE IN COUNTERMEASURE AGAINST LIQUEFACTION Download Article

    Morikawa Yukihiro, Maeda Kenichi and Zhang Feng
    • Article Type: Research Article
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    • Pages (1003-1008)
    • No of Download = 877

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    Liquefaction usually occurs in many sandy grounds during earthquake including Japan. Liquefaction causes damage of structures by making floatation or subsidence of them, and reduces the necessary performance of the structures. For example, stability of retaining wall based on skeleton weight of the structure is reduced due to subsidence and inadequate support which causes the destabilization of the structure. In addition, the light weight underground structure suffers damage such as floating due to the reduction of shear strength of soils during liquefaction. The damage occurs not only to the civil engineering structures (roads, bridges, etc.) but also to the residential buildings which makes the building unusable. On the other hand, Aichi Prefecture (Japan) is a center of the production of tiles where the crushed tile can be used as recycling materials for a measure of soil liquefaction. In this research, we have investigated the material property of the crushed tile and examined the effectiveness of countermeasure against liquefaction by shaking table tests. It is found that liquefaction of the ground can be reduced using crushed tiles because of its high friction and drainage properties. In the research, we found that the anti-liquefaction manhole which was backfilled by clashed tile floated only by 1/3 of the magnitude observed in the case of without countermeasure against liquefaction.

  13. EFFECT OF FLY ASH ON THE STRENGTH OF CONCRETE MADE FROM RECYCLED AGGREGATE BY PULSED POWER Download Article

    Eva Arifi, Achfas Zacoeb and Mitsuhiro Shigeishi
    • Article Type: Research Article
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    • Pages (1009-1016)
    • No of Download = 960

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    The performance of concrete made from recycled aggregate that produced by pulsed power technology due to the use of fly ash has been studied. Pulsed power technology has been proven to reproduce high quality recycled aggregate. Concrete made from 100% recycled coarse aggregate by pulsed power discharge can reach similar compressive strength to natural coarse aggregate concrete. The use of JIS type II fly ash as cement replacement of 25% and 50% mass without adjustment of water to cement ratio can reduce the compressive strength of concrete. However, with the same fly ash percentage, in 28 day of age, concrete made from recycled aggregate by pulsed power technology results better strength by 10.0% and 15.8% compared to natural aggregate concrete for 25% and 50% of fly ash, respectively. In addition, mixing method using two-stage mixing approach (TSMA) has been applied to improve concrete strength. This method in making recycled aggregate concrete can improve the strength of fly ash concrete made from recycled aggregate concrete up to 4.7%. Replacing 25% of cement mass with fly ash for concrete made from recycled aggregate by pulsed power technology has shown preferable result in strength, and can be improved by using TSMA method in mixing process.

  14. ESTIMATION OF BLAST LOADS FOR STUDYING THE DYNAMIC EFFECTS OF COEFFCIENT OF FRICTION ON BURIED PIPES BY SIMULATION Download Article

    Akinola Johnson Olarewaju
    • Article Type: Research Article
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    • Pages (1017-1024)
    • No of Download = 1470

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    In the study of dynamic behavior of buried structures due to blast by simulation, ground media, structures, blast loads, etc. are required. In this study, different types of blast scenarios and blast loads for various explosives were considered using [10]. Consequently, ground movement parameters were estimated and blast load durations for studying the dynamic effects of coefficient of friction on buried pipes due to blast loads by simulation were estimated. Simulated models for ‘slip’ and ‘no-slip’ conditions were analyzed using explicit code in ABAQUS with ‘no-slip’ condition serving as control. Dimensional analysis was used to further
    process the results. From the results, it was observed that the ground shock parameters attenuate greatly in ground media as the distance increases. In addition, it was observed that duration of blast play a significant role in the behavior of buried structures while the observed parameters reduced at coefficient of friction of 0.8 compared to the conventional coefficient of friction for static analysis. Parameters thus determined would help in the dynamic behavior study of buried structures due to blast using numerical codes like ABAQUS. This is with a view to designing buried structures like pipes to resist the effects of blast. Consequently, the environmental risk and hazards caused by blasts would be greatly reduced.