Articles

  1. CHARACTERIZATION OF INHERENT RANDOM HETEROGENEITY OF WEATHERED GRANITE Download Article

    Athapaththu A.M.R.G. and Tsuchida T.
    • Article Type: Research Article
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    • Pages (1025-1032)
    • No of Download = 924

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    Soils derived from granitic rocks exhibit a complex degree of variability in space. A grid was established having 5 m intervals spanning 50 m in length and 20 m in width in order to investigate inherent random heterogeneity of areas covered with weathered granite. Six major patterns of cone resistance varies with the depth were identified. Main grid was further divided at selected locations in 1m grids and at one location in 25 cm grids spanning 1 m in both directions for better understanding of spatial variability at close proximity. The analyses revealed that the coefficient of variation of cone resistance can be presented as 20% independent of the depth. Geo-statistics has been shown to be a useful technique in the assessment of inherent random heterogeneity of weathered granitic profiles. Semi-variogram analyses showed that the Spherical Models is best fitted to represent the spatial autocorrelation and prediction of cone resistance for areas covered with weathering remnants of granitic rocks.

  2. EFFECT OF LIME AND STONE DUST IN THE GEOTECHNICAL PROPERTIES OF BLACK COTTON SOIL Download Article

    Ankur Mudgal, Raju Sarkar and A.k. Sahu
    • Article Type: Research Article
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    • Pages (1033-1039)
    • No of Download = 737

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    In the present study Black Cotton Soil was stabilized with a mixture of lime and Stone Dust. First an optimum value of lime was determined on the basis of some geotechnical properties of mixture of lime and Black Cotton Soil. Then Stone Dust was mixed upto 25% by weight with an increment of 5% in the optimized mixture of lime-Black Cotton Soil. California bearing ratio, unconfined compression strength and maximum dry density values were determined of these modified mixes. Morphology of the soil and admixture has been studied by Scanning electron microscope (SEM), while mineralogical composition has been determined by X-Ray diffraction technique (XRD).

  3. EFFECT OF SILT CONTENT ON THE ANISOTROPIC BEHAVIOUR OF SILT-SAND MIXTURES Download Article

    Navid Khayat
    • Article Type: Research Article
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    • Pages (1040-1046)
    • No of Download = 341

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    The anisotropy of sand has not been fully studied in terms of the effects of different silt content. This study investigates the effects on anisotropy in Tehran sand with various silt contents. The tests performed in this research include some Hollow Cylinder Torsion Shear Tests conducted on 400kPa confining stresses. The samples had 0, 15, 30, and 50 percent silt contents, and the effect of the inclination angle on the major principal stress "α" was investigated with a particular emphasis on silt content. The parameter "α" is considered as the key parameter that indicates the anisotropy characteristics, and can vary from 0 to 90. According to the results, an increase of "α" leads to more contractive behaviours in the studied sands. In all samples, increasing the silt content up to 50% causes the strength to decrease.

  4. EFFECT OF WATER MANAGEMENT BY DRIP IRRIGATION AUTOMATION CONTROLLER SYSTEM ON FABA BEAN PRODUCTION UNDER WATER DEFICIT Download Article

    Mansour, H. A., Sabreen, Kh. Pibars, M. Abd El-Hady and Ebtisam I. Eldardiry
    • Article Type: Research Article
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    • Pages (1047-1053)
    • No of Download = 798

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    Field experiments were carried out at the Agricultural Research and Production Station, NRC, El-Nubaria district, Egypt during the winter season of 2012 and 2013 growing seasons in a sandy soil with Faba bean (Vica Faba L.G461) under automation controller drip irrigation system, to study the effect of water deficit (50, 75, and 100 % FC, field capacities) and compost tea additions (100 and 50 liter/fed) on faba bean yield, water and fertilizers use efficiency (WUE, FUE). The obtained results showed that the faba bean yield, WUE and FUE were superior by using compost tea (100 liters/fed and100 % FC) while the lowest values results were attained after using 50 liters/fed compost tea and 50 % FC. It could be concluded that the biggest added amount of compost tea 100 liters/fed impacted positively on Faba bean plants because they contain more amount of macro and micro nutrients and it helps save water under sandy soil conditions. Faba bean plants avoid the water stress under 100 % FC but adversely affected by water stress under FC (50 and 75%).

  5. AN EMPIRICAL MODEL FOR PREDICTING HYDRAULIC CONDUCTIVITY OF MINE TAILINGS Download Article

    Mary Ann Q. Adajar and Mark Albert H. Zarco
    • Article Type: Research Article
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    • Pages (1054-1061)
    • No of Download = 535

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    To evaluate the applicability of mine tailings as embankment materials, its geotechnical characteristics have to be established. Standard ASTM procedures are performed to determine the physical properties and hydraulic conductivity of mine tailings from three (3) different mining sites in the Philippines. Falling head permeability tests are performed on reconstituted samples compacted at varying void ratio and fine content. The hydraulic conductivity, k of tailings falls within the range of 10-3 to 10-6 cm/sec. Data obtained from these tests are used to develop an empirical model for predicting the hydraulic conductivity of mine tailings under fully saturated conditions as a function of void ratio and fine contents. The formulated model is a useful tool to estimate the hydraulic conductivity of non-plastic fine tailings, a parameter needed in seepage analysis, when these waste materials are used as embankment materials in the construction of tailing dams.

  6. NUMERICAL SIMULATION OF RIGID PAVEMENT BEHAVIOR TO NON-DESTUCTIVE IMPULSE RESPONSE TESTING Download Article

    Hudson Jackson and Kassim Tarhini
    • Article Type: Research Article
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    • Pages (1062-1069)
    • No of Download = 529

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    The Impulse Response (IR) technique is a stress wave method that measures the structure’s response to stress waves generated by an impact source. When applied to rigid pavements, the measured response contains complex information on the dynamic pavement properties that is primarily used in detection of voids or loss of support, and softening of the subgrade. The dynamic response of the pavement system is assumed to be similar to that of a single degree of freedom (SDOF) system. This assumption is useful for practical purposes but introduces inconsistencies and uncertainties in the data interpretation because it oversimplifies a complex dynamic problem. Results of a Finite Element parametric study analysis conducted to identify key factors that influence rigid pavement response during Impulse Response (IR) testing are presented. A dynamic modal analysis of a multilayer rigid pavement, assuming viscoelastic and elastic linear material properties, indicates that the mobility spectra from IR testing is predominantly influenced by the properties of the surface layer and the subgrade. The presence of voids beneath a rigid pavement results in increased mobility and less damped behavior of the pavement. The validity of the SDOF assumption in void detection in the reduction of field IR data is also examined.

  7. EFFECT ON UNCONFINED COMPRESSIVE STRENGTH OF SAND TEST PIECES CEMENTED WITH CALCIUM PHOSPHATE COMPOUND Download Article

    G. G. N. N. Amarakoon, Takefumi Koreeda, Satoru Kawasaki
    • Article Type: Research Article
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    • Pages (1070-1075)
    • No of Download = 806

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    Chemical grout is composed of a calcium phosphate compound (CPC) which develops to form calcium carbonate (CC) precipitation throughout the soil and leading to an increase in soil strength. In this paper, initially the condition for CPC precipitation by using different mixtures of calcium and phosphate stock solutions were investigated and analyzed. For that, Toyoura sand test pieces were cemented by CPC solutions and cured up to 28 days and carried out unconfined compressive strength (UCS) test. Moreover, Toyoura sand test pieces were cemented by CPCs with scallop shell (SS) powder and cured and these specimens also analyzed with UCS tests. The UCS of the sand test pieces cemented by CPC with SS powder was larger than that of the test pieces with no added powders. The UCS of Toyoura sand test piece cemented with the CPC-SS powder method increased to a maximum of 156.9 kPa. Moreover, the best CPC-Chem mixture for cementation is CA: DPP with the concentration of Ca/P ratio is 0.5. In addition pH concentration, scanning electron microscope (SEM), and density before and after curing were observed. The results indicate that the density and the pH concentration of the sand test pieces cemented by CPCs with SS powder were larger than that of the sand test pieces with no added powders. SEM images of test pieces cemented with CA: DPP mixture by addition of SS powders not clearly identified a crystal formation among particles of Toyoura sand.

  8. VULNERABILITY ASSESSMENT OF NON ENGINEERED HOUSES BASED ON DAMAGE DATA OF THE 2009 PADANG EARTHQUAKE IN PADANG CITY, INDONESIA Download Article

    Rusnardi Rahmat Putra, junji Kiyono and Aiko Furukawa
    • Article Type: Research Article
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    • Pages (1076-1083)
    • No of Download = 1017

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    Several powerful earthquakes have struck Padang during recent years, one of the largest earthquake event was an M 7.6 that occurred on September 30, 2009 and caused more than 1000 casualties. Following the event, A 12-site microtremor array investigation to gain a representative determination of the soil condition of subsurface structures in Padang has been conducted. From the dispersion curve from the array observations, the central business district of Padang corresponds to relatively soft soil condition with Vs30 less than 400 m/s. Because only one accelerometer was existing, the 2009 Padang earthquake was simulated to obtain peak ground acceleration for all sites in Padang city. By considering the damaging data of the 2009 Padang earthquake for engineered houses, Seismic risk vulnerability estimation of non-engineered houses for rock, medium and soft soil condition can be obtained, and also estimate the loss ratio based on the ground response, seismic hazard of Padang and the existing damaged to non-engineered structure houses due to Padang earthquake in 2009 data for 500 return periods of earthquake events.

  9. FUNDAMENTAL PROPERTIES AND ANALYSIS OF WATER QUALITY IN A RESERVOIR AFFECTED BY LITTLE WATER USE AND TEA PLANTATION Download Article

    Masaaki Kondo and Takamitsu Kajisa
    • Article Type: Research Article
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    • Pages (1084-1089)
    • No of Download = 556

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    There are many reservoirs in trouble on eutrophication problem. This paper focused on a reservoir whose water has rarely been used for agriculture or drinking. The many tea plantations distributed in the dam basin are suspected to be the cause of the reservoir’s eutrophication. It was investigated that eutrophication components such as nitrogen and phosphorus and how they relate to the tea plantations in the basin. With reference to phosphorus, trophic levels were determined with Vollenweider plots and Carlson indices. With reference to nitrogen, a field survey was carried out to investigate the properties of sulfate and then sulfate concentration was analyzed with a simple model. The various activities to improve the water quality of the reservoir are introduced. In conclusion, the dam reservoir water is typically eutrophic, and might be affected by the fertilizer in tea plantations. The motion of surface water in the dam reservoir is similar with the property of river, and then the sulfate concentration was analyzed with simple model.

  10. INVESTIGATION OF CARBON FOOTPRINT AWARENESS USING TRAVEL DIARY METHOD Download Article

    Nur Sabahiah Abdul Sukor and Nur Khairiyah Basri
    • Article Type: Research Article
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    • Pages (1090-1095)
    • No of Download = 459

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    In this study,100 university students were recruited to complete a seven day travel diary that described their use of privately owned motor vehicles in order to discover their underlying psychological factors that affected the production of individual carbon footprints through travel patterns. The diaries were collected and the respondents were given a motivation session related to carbon emissiona caused by motor vehicles. They were then asked to record their travel patterns for a further seven days and encouraged to change their travel patterns to be more pro-environment. A statistical analysis was performed to examine the differences of these individual’s carbon footprints; before and after the motivation session. The results revealed significant differences in carbon footprints between first and second travel diaries. The structural equation modeling demonstrated that among the psychological variables, pro-environment attitude was the most significant factor affecting the respondent’s intention to reduce their usage of motor vehicles; thus influencing the respondents’ behavior to be more pro-environmentalist. As a conclusion, this study suggests that individual carbon footprint can be measured through travel diary method.

  11. CONSERVATION AND EXPLOITATION OF BANG GRASS EFFECTIVE IN PHU MY VILLAGE, VIETNAM Download Article

    Duong Minh Truyen, Le Hong Thia and Mashhor Mansor
    • Article Type: Research Article
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    • Pages (1096-1100)
    • No of Download = 448

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    Phu My located in Kien Giang province, South of Vietnam is a small village with the majority of the population made of a Khmer community. The weather conditions are not encouraging for locals due to serious flooding months. The soils and water are comparatively acidic. Therefore, only Bang grass (Lepironia articulate) – an indicator for the wetland habitats and Nang grass (Eleocharis dulcis.) – the main food of an endangered Sarus Crane (Grus antigone) can thrive. Bang grassland area decreased due to the housing problem. To overcome the decrease of Bang grass and conserve this species, the project “Restoration and sustainable exploitation Bang grassland in Phu My, 2004” conducted to help locals make sophisticated handmade products from Bang grass. It is a good way to help the locals to benefit and conserve Bang grass.

  12. PROPAGATION OF HARMONICAL VIBRATIONS IN PEAT Download Article

    Darius Macijauskas and Stefan Van Baars
    • Article Type: Research Article
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    • Pages (1101-1106)
    • No of Download = 585

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    In order to check the reliability of man-made vibration prediction methods, vibration tests were performed on one of polders in the North-West of the Netherlands. The polder was chosen because it has a rather homogenous, thick and soft peat top layer. Here sufficient harmonical vibrations could be generated by a rather small shaker. The shaker was designed and manufactured in order to produce harmonical vibrations at the soil surface. It consists of two counter rotating electric vibrators (with rotating eccentric masses) in order to produce a vertically oscillating force. For the recordings of the vibrations, six 2D or 3D geophones were placed on the soil surface and one 2D geophone was placed on top of the shaker. The measured vibration amplitudes of the vertically oscillating shaker were compared with 1. Two different analytical methods used for the design of vibrating machine foundations, 2. The Confined Elasticity approach and 3. The Finite Element Method, for which Plaxis 2D software was used. Also the measured vibration amplitudes at the soil surface were compared with Barkan-Bornitz’s solution and Finite Element Modeling.

  13. MODELLING OF SHEAR STRENGTH PARAMATERS OF SATURATED CLAYEY SOILS Download Article

    Inanc Onur, Burak Evirgen, Ahmet Tuncan and Mustafa Tuncan
    • Article Type: Research Article
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    • Pages (1107-1110)
    • No of Download = 1091

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    Shear strength of a soil can be defined as the maximum shear stress that can resist by the internal forces of the soil. Shear strength must be determined to solve the soil stability problems. The shear strength parameters of the soil are cohesion and internal friction angle. These parameters can be determined in the laboratory by the direct shear test, triaxial test and unconfined compression test. However, laboratory tests take time and engineers want to define these parameters easily by using software. The development of the computer technology presents abilities to model the soil behavior in civil engineering applications. In this study, triaxial compression tests are performed on saturated clayey soils under different confining pressures. Unconsolidated-Undrained test is chosen to identify short term behavior. After the experimental procedure, the test is modeled by using the Plaxis program and the results are compared. Relationship between the results are presented.

  14. EFFECTIVENESS OF REINFORCEMENT IN EMBANKMENT GROUND SUBJECTED TO REPEATED SHEAR DEFORMATION Download Article

    Yusaku. Isobe, Hossain Md. Shahin and Teruo Nakai
    • Article Type: Research Article
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    • Pages (1111-1116)
    • No of Download = 899

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    In this research, a comparative study is done on the effectiveness of reinforcement in embankment ground. The restraint effect of ground displacement by reinforcement of sheet pile and the sheet pile combined with the nailing method are investigated by model tests and corresponding finite element analyses. An elastoplastic model and subloading tij model are used in the analyses. Two loading conditions were applied namely, the simple vertical loading to the footing and cyclic loading associated with repeated shear deformation in the ground for both series of the model tests and the finite element analyses. Soil-water coupling analysis applying an inertial force to real ground embankment is also performed. It is revealed that when the bearing capacity of the ground increases, the lateral and vertical displacements are restrained. The reinforcement by the sheet pile combined with the nailing method is effective compared with that of the sheet pile alone.