Articles

  1. TEMPORAL VARIATIONS IN PERCHED WATER AND GROUNDWATER QUALITIES AT AN OPEN SOLID WASTE DUMPSITE IN SRI LANKA Download Article

    Udayagee Kumarasinghe, Y. Inoue, T. Saito, M. Nagamori, Y. Sakamoto, M.I.M. Mowjood, and K. Kawamoto
    • Article Type: Research Article
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    • Pages (1-8)
    • No of Download = 702

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    Open dumping of municipal solid waste is a common practice in many developing countries and contaminates surface and groundwater in the vicinity. In this study, long-term monitoring was conducted at an abandoned solid waste dumpsite to characterize temporal variations of perched water and groundwater qualities. The dumpsite was located at Udapalatha PS in Central Province of Sri Lanka and consisted of two sections (namely Old and New sections). The Old section was used for waste dumping for seven years from 2003 to 2010, and the New section was used for six months in 2011. Multiple wells were installed at each section and water qualities monitored for two years from May 2013 to March 2015. Water quality parameters such as pH, EC, BOD, COD, TN, TP, major cations, major anions, and heavy metals were measured monthly. Leachate pollution index (LPI) was used to quantify the leachate contamination potential of landfill site. Results showed that groundwater samples from both Old and New sections exhibited relatively low LPI during the monitoring period, whereas perched water samples from New section showed high LPI with fluctuations. At the monitoring site, perched water and groundwater seem to persist as two independent bodies for both Old and New sections. Especially, the dumped waste at lower layer at the Old section was fully washed out by rainfall and surface water after waste dumping and currently carries a low risk of groundwater contamination.

  2. THE ESTIMATION OF BEARING CAPACITY AND SWELL POTENTIAL OF DEEP SOIL MIXING ON EXPANSIVE SOIL BY SMALL SCALE MODEL TEST Download Article

    Yulvi Zaika and Arief Rachmansyah
    • Article Type: Research Article
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    • Pages (9-15)
    • No of Download = 796

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    Deep Soil Mixing (DSM) is a ground modification technique to improve soil characteristic. This paper explain the result of laboratory experiment of deep soil mixing (DSM) in small scale. The model have been constructed to estimate field condition. The important properties of expansive soil such as the strength and swelling were investigated. The fly ash was used as binder material to enhance strength and mitigate swell potential. However optimum binder dosage, water – binder ratio and geometrical column (length, diameter and spacing) influenced performance of DSM. Variation of length and spacing of column could be established by considering active zone and the area ratio in the single square arrangement. The required treatment area are determined based on tolerable swelling and allowable bearing capacity. The small scale of DSM construction showed significant improvement of swell and strength properties compare with untreated soil. The empirical model are presented in this research provided reasonable predictions of strength and swelling for in situ condition.

  3. INFLUENCE OF DEFORMATION MODULI ON THE SETTLEMENT OF EARTH DAMS Download Article

    Smail Nadia and Rouissat Bouchrit
    • Article Type: Research Article
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    • Pages (16-22)
    • No of Download = 636

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    The efficiency of compaction of earth dam’s embankment is influenced by the initial characteristics of the soils, namely the deformation modulus and density. These two parameters automatically affect the deformations of the dam which can directly impact on its safety. The modeling of these deformations is an essential investigation allowing the comprehension of the dam’s behavior. The main objective of modeling is to analyze the behavior of the dam and compare it with monitoring data. A lot of difficulties are recorded for the estimation of embankments deformation moduli required for modeling. A parameterized analysis in relation to the variation of this parameter is necessary for the estimation of earth dam’s settlement. The present study concerns the parameterized analysis of the correlation between the parameter influencing compaction, especially deformation modulus, and the deformations of the dam. An application carried out on the Boughrara dam in the region of Tlemcen in the north-west of Algeria is presented. The modeling result is compared with the monitoring measurements of dam. This study led to the verification of the compatibility, for different values of deformation modulus, between the settlement of the dam by modeling and by monitoring in order to validate the mechanical behavior of the dam.

  4. EVALUATION OF VARIOUS INTERPOLATION TECHNIQUES FOR ESTIMATION OF SELECTED SOIL PROPERTIES Download Article

    R. S. Morgan, M. Abd El-Hady, I. S. Rahim, J. Silva and S. Ribeiro
    • Article Type: Research Article
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    • Pages (23-30)
    • No of Download = 567

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    Efficient soil management practices depend on the spatial distribution of soil properties which varies significantly even within the same field. Considering that it is impossible for any monitoring technique to provide spatially continuous data, spatial interpolation plays an indispensable role in estimating the missing values where no actual value was measured. The objective of this study was to evaluate various interpolation techniques for the estimation of selected soil chemical properties in a study area located about 85km to the north west of Cairo, Egypt. The studied soil properties included soil salinity, available phosphorus and nitrogen. The interpolation techniques included two commonly used techniques namely, Ordinary Kriging (OK) and Inverse Distance Weighting (IDW).The Artificial Neural Networks (ANN) method, which is considered a somewhat new approach was also evaluated. Soil samples were collected at approximately 200×200 m grids at 0-25 cm depth. The cross-validation method was used for evaluating the selected methods utilizing root mean square error (RMSE) and mean relative error (MRE). This study revealed that ANN had the highest accuracy followed by OK then IDW in terms of both RMSE and MRE when interpolating the studied soil properties. Nevertheless, these results are dependent on the accuracy of the designed network which must have an overall accuracy of coefficient of correlation (R) more than 0.80 between the predicted and the actual data. It also revealed that the best IDW with the highest accuracy must have a power of 2 for salinity and nitrogen and a power of 3 for phosphorus.

  5. GREEN SUPPLY CHAIN IMPLEMENTATION IN MANUFACTURING INDUSTRY: A CASE STUDY Download Article

    Alina Shamsuddin, Eta Wahab, Nor Hazana Abdullah and Fawad Habib Qazi
    • Article Type: Review Article
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    • Pages (31-37)
    • No of Download = 467

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    This paper is a case study in Malaysia which examines the level of implementation of Green Supply Chain Management (GSCM) practices in Malaysia. The findings serve as an indicator to the future prospects of GSCM in Malaysia. The study was carried out in the manufacturing industry as the manufacturing industry produces more emissions compared to other industries. A quantitative method was adopted. Questionnaires were sent to the employees of the manufacturing companies and the data was analyzed using the Statistical Package for Social Science (SPSS) program. The levels of implementation of the manufacturing companies were determined using a descriptive analysis. The results indicate that the company had a medium implementation level of GSCM practices. From the results, it can be concluded that the manufacturing companies are aware of green practices but are not able to implement it out in each of the supply chain key processes.

  6. ASSESSING THE EFFECT OF PREDICTED CLIMATE CHANGE ON SLOPE STABILITY IN NORTHERN THAILAND: A CASE OF DOI PUI Download Article

    Thapthai Chaithong, Suttisak Soralump , Damrong Pungsuwan and Daisuke Komori
    • Article Type: Research Article
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    • Pages (38-48)
    • No of Download = 622

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    Landslide is a natural disaster which occurs very often in mountainous areas. Climate is an important determinant on the amount of moisture in the ground, which is a key to the stability of soil slope. Therefore, climate change due to the global warming may affect the intensity of rainfall and the evaporation in the future and influences situation of slope stability in a long time. The purpose of this study is to propose a method for assessing the effect of climate change on slope stability using general circulation model (GCM). A method for predicting climate change impact on slope stability is to link the antecedent precipitation index (API), hydrological model, obtained through downscaling GCM to critical antecedent precipitation model. The GCM is downscaled using a dynamical technique to derive regional climate models. Then a statistical correlation is used to adjust for the basis of the regional climate model. The GCM used in this study is the ECHAM4/OPYC3 model. The analysis found that the trend of susceptibility to slope failure depends on the pattern of simulated rainfall and the recession constant of the antecedent precipitation index.

  7. SLOPE STABILITY ANALYSIS USING MINI PILE: A CASE STUDY IN CIGEMPOL RIVER, KARAWANG, WEST JAWA Download Article

    Niken Silmi Surjandari, R. Harya Dananjaya and Etika Cahyaning Utami
    • Article Type: Research Article
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    • Pages (49-53)
    • No of Download = 645

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    Several slope failures have occurred in the Cigembol River, Karawang, West Java. The problem could be tackled by increasing the slope using appropriate slope countermeasures and analysis. For this study an installation of mini piles was selected. The purpose of this study was to compare the safety factor of the slope before and after installation of such mini piles using soil revetment. The analysis was carried out with the finite element method. For the purpose of this analysis, the only loads considered were those of self-weight. The results show that the safety factor of the existing slope is 1.068. After installation of the mini piles, the safety factor increases to about 1.295–1.982. For the piles revetment, the optimum dimension, depth, and spacing of piles was 25 × 25 cm, 10 m, and 2 m respectively. The stability analysis of the some configuration of mini pile demonstrate that the installation of the mini pile may cause increasing the safety factor, and show there was optimum configuration mini pile model.

  8. EFFECT OF GRAVEL CONTENT ON SOIL SUCTION Download Article

    Yaxu Liu, Ivan Gratchev, Somayeh Saeidi and Sameera Pitawala
    • Article Type: Research Article
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    • Pages (54-58)
    • No of Download = 614

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    This paper seeks to a) investigate the effect of gravel on soil suction and b) establish whether results of standard suction tests using filter paper can accurately represent the value of suction that would be expected in the field. Eight natural soils with different soil gradation and plasticity were used to prepare two types of specimens: a) the “original” specimens (no change compared to the field soil), and b) “sieved” specimens – when the “original” soil was passed through a 2-mm sieve to meet the standard requirement. Comparisons of soil-water characteristics curves (SWCC) obtained for both types of specimens were made to better understand the effect of gravel content on total and matric suction. The obtained data indicated that the results of standard tests can significantly overestimate the soil suction. In particularly, it was found that as the gravel content increased from 4.8 to 19.6%, the difference in suction between the “original” and “sieved” specimens increased to 14% (total suction) and almost 20% (matric suction). The experimental data showed that the effect of gravel was more pronounced for low plasticity soils, compared to high and very high plasticity soils, in which the influence of gravel on suction was found to be insignificant. Although the “sieved” specimens tended to produce higher values of suction, this tendency might reverse for high and very high plasticity soils when their liquidity index (LI) became positive.

  9. OEDOMETRIC STUDY OF DREDGED MARINE SOILS ADMIXED WITH SAND FOR SETTLEMENT REDUCTION Download Article

    Siti Farhanah S.M Johan and Chee-Ming Chan
    • Article Type: Research Article
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    • Pages (59-62)
    • No of Download = 556

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    Dredged marine soils (DMS) can be reused as fill materials for land reclamation project other than dump back to the open sea. However, in Malaysia, dredged marine soils were considered as a geowaste because of it has poor engineering properties. In the present study, dredged marine soils were excavated from the dredging works near the jetty of Kuala Perlis, Malaysia. To investigate the settlement reduction of DMS, a sand-mixed was used in this study and these results were compared with natural DMS (without sand). Oedometer test were conducted to calculate the consolidation properties of DMS and k-value can be obtained from the test. The test results showed that the dissipation of water from soils occurs faster in the sand-mixed compare to the control sample (without sand) due to the drainage path that have been reduced (two-way drainage).

  10. MEASUREMENT OF THE NATURAL FREQUENCY AND DEFLECTION OF THE WIDESPAN-FLOOR SYSTEM DUE TO DYNAMIC LIVE LOAD Download Article

    Bambang Supriyadi
    • Article Type: Research Article
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    • Pages (63-68)
    • No of Download = 668

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    Study on the natural frequency of a floor-structural system is a key parameter to determine how the floor system will respond to forces causing vibrations. Measurement of frequency and displacement of the floor system was the focus of this research. The main objective of this investigation is to develop a boundary of the natural frequency of the floor system for the widespan building. The observation was conducted for two different human activity that is walking (during graduation ceremony) and dancing (during live music). The results of the study shows that the frequency of floor system due to human walking activity was measured between 3.54 to 5.32, while, rhythmic dance and jumping activity yields the frequency between 4.17 to 5.08 Hz. At the range of the measured frequency, the human walking induced maximum deflection of the floor about 1.76 to 7.81 mm. The deflection is double about 15.36 to 33.18 mm when 30 to 35 peoples were dancing/jumping in unison in response to live music.

  11. ON THE NAILED SOIL SLOPES RESEARCH DEVELOPMENT Download Article

    As’ad Munawir
    • Article Type: Research Article
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    • Pages (69-78)
    • No of Download = 454

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    The slope stability was researched over the past decades, understandings the behavior of nailed soil slopes, with their properties and characteristics, have guided to development of enhanced recognizing of the variation in nailed soil slopes parameters. Failures can arise over time, hence the identification of the necessities and the restrictions of laboratory and in situ testing for evaluating nailing parameter have to be deeply understood. Many researcher have enriched and refined the knowledges of the principles of soil nailing mechanics that associate soil behavior to slope stability and factor of safety. This paper is aimed to explore some of important state of the art development of nailed soil slope and analytical techniques extended by extensive investigation of the mechanics of slope stability analyses. The most significant effective parameter that play important role in slope safety factor in almost of many works are length, nailing angle, and distance between center to center of nails. Slope angle, connection of nailed head, the distance with toe and nail diameter were also the points that cannot be neglected in their study. Choosing the proper cable or pile element in the finite element modeling and the mobilized both axial and shear forces are also reviewed in this paper.

  12. TUNNEL CONSTRUCTION IMPACT ON GROUNDWATER CHARACTER OVER 25 YEARS OF OBSERVATION AT MATSUMOTO TUNNEL, MATSUMOTO CITY, JAPAN Download Article

    Hiroyuki Ii
    • Article Type: Research Article
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    • Pages (79-88)
    • No of Download = 485

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    Over 25 years, approximately 11 million m3 of water inflow in the Matsumoto tunnel at the north of Matsumoto city was drained. Water inflow in the tunnel during tunnel construction varied from 1 to 8 m3 per minute decreasing to 1 to 0.6 m3 per minute between 1993 and 1995. At present, inflow maintains a rate of 0.6 m3 per minute. Currently, it remains at 0.6 T.U. (Tritium Unit) and the age of water in flowing into the tunnel has been estimated to be over 30 years old from initial 3H concentration for surface water which varied from 4 to 10 T.U. As oxygen stable isotope values and HCO3- concentration of water inflow in the tunnel were uniform for 25 years, the source of water inflow in the tunnel is not thought to have changed. Roughly 14 to 39 million m3 water was still stored in rocks above the tunnel in the plateau from 10 % porosity measured by rock sample. When only 3 million m3 groundwater, less than one tenth of porosity coincided with effective porosity (0.48 %) or specific yield (0.6 to 1.2 %) was drained, groundwater level decreased widely. Drained water after over 25 years of tunnel construction was derived from unsaturated small pore water excluding main pores or cracks. Therefore, total pore volume was used for slow groundwater migration (flow velocity is 3 to 7 m per year). Cracks or main pores connecting with many pores were important for fast groundwater migration (flow velocity is over 100 m per year).

  13. PRIMARY POLLUTANT SELECTION AND DETERMINATION OF WATER QUALITY INDEX IN CLASS DISCHARGE DIVISION BASED ON THREE CLASS MARKOV MODEL Download Article

    Mariana Marselina, Arwin Sabar, Indah R S S Salami and Dyah Marganingrum
    • Article Type: Research Article
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    • Pages (89-96)
    • No of Download = 500

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    This study aims to identify how the dominant parameter selection may show pollutants source in every segment of the reservoir, be it reservoir input segment, reservoir middle segment or body reservoir segment, and reservoir outlet segment that turns out to be diverse. Water Quality Index (WQI) value in this study was calculated for each parameter chosen based on the Principal Component Analysis (PCA). In addition, this study showed that pollution in the rainy season was lower that the pollution in the dry season, this was indicated by the WQI values obtained. This study also showed that the reservoir input pollution source was dominated by domestic activities and industry, while the middle segment of the reservoir usually polluted by floating nets activity, and in the reservoir outlet, pollutant accumulation occurred as indicated by the presence of H2S as the main pollutant.

  14. THE COMPARATION OF BACK PROPAGATION METHOD AND KOHONEN METHOD FOR GAS IDENTIFICATION Download Article

    Riki Mukhaiyar
    • Article Type: Research Article
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    • Pages (97-103)
    • No of Download = 612

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    The identification process of gas flavor is conducted by using the output of gas sensor system to recognize a variety of gas flavor. The identification and analysis process of this system is processed by using an artificial neural network approaches those are back propagation and Kohonen method. According of the experiment’s result, the best parameter for back propagation network is the momentum constant (α) = 0.7, the constant of the sigmoid function (β) = 4.5, constant learning (η) = 0.9, and the constant of convergence (ε) = 0001, convergence is achieved more or less in the 19 500 iterations (± 16 seconds). Meanwhile, the best classification for Kohonen network is for the output of 8 knots with an average of 80.7% uniformity (for a maximum of 500 times iteration, approximately ± 3 seconds). Thus, the best network to classify the signal pattern of gas flavor is back propagation network for the parameters (α) = 0.7, a constant sigmoid function (β) = 4.5, a constant learning (η) = 0.9, and a constant convergence (ε) = 0001.

  15. SETTLEMENT REDUCTION OF DREDGED MARINE SOILS (DMS) ADMIXED WITH CEMENT & WASTE GRANULAR MATERIALS (WGM): 1-D COMPRESSIBILITY STUDY Download Article

    Mohammad Zawawi Rosman and Chee-Ming Chan
    • Article Type: Research Article
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    • Pages (104-110)
    • No of Download = 495

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    Dredged marine soils (DMS) are considered as geo-waste and commonly disposed far into the sea. Environmental impacts raised from dredging such as turbidity and disturbance of marine ecosystem had increased the social demand to reuse DMS in engineering application. Typically, DMS have low shear strength and low bearing capacity. Hence, the DMS could be strengthened up by soil solidification. In present study, waste granular materials (WGM) such as coal bottom ash (BA) and palm oil clinker (POC) were utilized as additional binder to cement. The DMS were solidified with 3 series of admixtures; namely cement and/or WGM. The factor that influenced the compressibility of the soil sample such as percentages of admixtures were considered. Proportioned samples of 10, 15 and 20 % of cement, and/or 50 and 150 % of WGM of dry weight of DMS were subjected to one-dimensional oedometer test. The test samples were cured for 7 days in room temperature. Results show that cement- and WGM-admixed DMS have reduced the soil’s compressibility considerably than the untreated sample. As expected, the cemented soil had significantly reduced the settlement better than WGM-admixed soil. Hence, homogeneous samples of 15C50BA and 10C100POC produced almost similar reduction of compressibility as sample 20C. Therefore, reusing WGM as partial replacement of cement in DMS could provide beneficial reuse of these materials.

  16. ADSORPTION OF NATURAL ORGANIC MATTER (NOM) IN PEAT WATER BY LOCAL INDONESIA TROPICAL CLAY SOILS Download Article

    Suprihanto Notodarmojo, Mahmud and Amanda Larasati
    • Article Type: Research Article
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    • Pages (111-119)
    • No of Download = 506

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    A series of experiment on the adsorption of natural organic matter (NOM) originated from peat water in Central Kalimantan, Indonesia by local peat clay soils had been carried out. A selected local peat clay soil (LPC) and activated local peat clay soil (ALPC) had been used as adsorbents. The activation of the local peat clay soil was carried out by immersing it in 1 M HCl solution at 900 oC. The effects of pH on the adsorption capacities were investigated. It has been found that at lower pHs (3-5) the adsorption capacities increased significantly. A rotary shaker was set at 180 rpm as an agitator in performing the kinetically behaviour and adsorption isotherm of NOM onto the LPC and the ALPC. It was found that the equilibration time for the LPC and the ALPC were 180 and 150 minutes, respectively. The kinetics equation model that most fitted to the adsorption experimental data for the both adsorbents was pseudo-second order kinetics model (r2 > 0.99). The Dubinin-Radushkevich depicted the data more accurately to describe the NOM-LPC and NOM-LAPC adsorption isotherms (r2 > 0.99). Further analysis on the peat water NOM characteristics and local clay (LPC and ALPC) suggested that physical adsorption, mainly electrostatic interactions enhanced adsorption process and hydrophobic or solute driven adsorption dominated in the early stage of the process, followed by a chemical adsorption process.

  17. ASSESSING THE IMPACTS OF CLIMATE CHANGE ON ROAD INFRASTRUCTURE Download Article

    Zeshen Shao, Graham Jenkins and Erwin Oh
    • Article Type: Research Article
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    • Pages (120-128)
    • No of Download = 514

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    There is an increasing evidence that the earth’s climate is changing with some of the changes attributable to transport infrastructure. Climate change can have impacts on road infrastructure. The direct impacts can be due to the effects of environment. Temperature can affect the aging of bitumen resulting in an increase in brittle failure of the surface seals that represent more than 90% of the rural sealed roads in Australia. Further, rainfall changes can alter moisture balances and influence pavement deterioration. Brittle failure of the bitumen causes the surface to crack, with a consequent loss of waterproofing of the surface seal. The result is that surface water will enter the pavement causing potholing and will cause rapid loss of surface condition. More frequent reseal treatments will overcome the problem, but this is at a higher cost to road agencies. Road infrastructure is a long-lived investment. An understanding of the expected impacts of future climate change by road designers, asset managers and planners, could produce considerable cost savings in the long term. This research aims to provide an assessment of likely effects on climate change for South East Queensland region in the next 90 years, and further identify and assess the likely effects of climate change on road pavement. It can be concluded that, climate change in South East Queensland does play a role in lower deterioration rates. The findings suggest that decreasing rainfall (decreasing TMI) will slow flexible pavement deterioration. However, increases in temperature are likely to cause materials to expand to affect pavement deterioration rates.

  18. EFFECT OF RUBBER POWDER PARTICLE ON THE STRENGTH OF FOAMED CONCRETE Download Article

    Siti Radziah Abdullah, Akhtar Izzaty Riwayat, A.S.M.Abdul Awal and M. Zakaria Hossain
    • Article Type: Research Article
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    • Pages (129-134)
    • No of Download = 727

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    Foamed concrete has become one of the most commercialized materials used in construction industry. It has different characteristics compared to conventional concrete such as self-compacting without vibration, flowability and low density. Even though foamed concrete has many advantages but it possess low strength limiting its use in many applications. This research aims to investigate the potential of foamed concrete incorporating rubber powder as additive to improve its strength. The amount of rubber powder added as filler in foamed concrete are 0%, 3%, 6%, 9% and 12%. A total of 15 concrete cubes and 15 concrete cylinders were cast with difference percentages of rubber powder in order to evaluate its compressive and splitting tensile strength. The mix design was set to achieve a density of 1800 kg/m3. The experiments on fresh state properties show that the foamed concrete has a very low workability as the percentage of rubber increase. However, the compressive and splitting tensile strengths for foamed concrete containing rubber are higher compared to control foamed concrete. The addition of 9% of rubber brought a significant increase for compressive strength and tensile strength of 122% and 43%, respectively, as compared to foamed concrete without rubber powder. Based on the results, it was concluded that the optimum percentage of rubber in this research was 9% for the highest compressive and tensile strength for foamed concrete.

  19. ESTIMATION OF VS30 BASED ON SOIL INVESTIGATION BY USING MICROTREMOR OBSERVATION IN PADANG, INDONESIA Download Article

    Rusnardi Rahmat Putra
    • Article Type: Research Article
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    • Pages (135-140)
    • No of Download = 641

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    Several powerful earthquakes have struck Padang during recent years, one of the largest of which was an M 7.6 event that occurred on September 30, 2009 and caused more than 1000 casualties. Following the event, we performed single observations of microtremors at 110 sites in Padang. The results enabled us to estimate the site-dependent amplification characteristics of earthquake ground-motion. We also conducted a 12-site microtremor array investigation to gain a representative determination of the soil condition of subsurface structures in Padang. From the dispersion curve of array observations, the central business district of Padang corresponds to relatively soft soil condition with Vs30 less than 400 m/s, the predominant periods due to horizontal vertical ratios (HVSRs) are in the range of 2.0 to 4.0 s. 

  20. LATERAL AND UPLIFT STATIC LOAD TESTS OF PRECAST CONCRETE PILE Download Article

    Jialin Zhou, Erwin Oh, Xin Zhang, Hongsheng Jiang, Peisen Wang, Wei Liu and Shuangli Wei
    • Article Type: Research Article
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    • Pages (141-148)
    • No of Download = 645

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    In order to perform environmental construction, eliminating the dust contamination caused by welding reinforcement cages and blending concrete onsite, as well as diminishing the noise pollution caused by striking precast piles, three non-displacement precast piles subjected to lateral loading and another three that were subjected to vertical uplift loading were tested. The lengths of these tested piles were 24.7m, 26.6m and 28m with the same cross-section. The soil was removed before these piles were placed in the required location. The horizontal and vertical movements of these piles under cycling loading and progressive loading were investigated through static load tests. Furthermore, six pairs of vibration wire strain gauges were welded in one pile which was applied with uplift loading for load transfer observation and shaft resistance analysis. Results suggest that the critical and ultimate loads of lateral loaded piles and ultimate loads of uplift loaded piles increase with the pile length, and in the pile with the welded gauges, that the axial force decreases with depth along the pile, increasing with applied loads provided by hydraulic jacks. In addition, the distribution of unit shaft resistances is determined and the propagations of friction resistances are analyzed.

  21. EFFECT OF LATERAL BOUNDARY CONDITION ON CONFINED -REINFORCED EARTH SUBJECTED TO DIFFERENTIAL SETTLEMENT Download Article

    Ho Manh Hung, Jiro Kuwano and Shinya Tachibana
    • Article Type: Research Article
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    • Pages (149-156)
    • No of Download = 582

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    A new method, the confined-reinforced earth (CRE) method, has been suggested to strengthen the subgrade layer, at the bottom of road pavement. The method uses granular soil, geogrids and confining tie rods. It is intended to reduce the damage from the large differential settlement between bridges or culverts and their approaches due to major earthquakes, and to make it possible for vehicles, especially emergency vehicles to pass the resulting unevenness. This study presents model tests designed to investigate the effects of the length of confined-reinforced earth by examining how lateral boundary conditions affect the consequences of differential settlement. Tests with two lateral boundary conditions, i.e. fixed-fixed (both ends of the geogrids are laterally fixed) and fixed-free (one end of the geogrid is laterally fixed and the other end is free) of the CRE method were performed and the effect of differential settlement was compared. The results show that the lateral boundary condition significantly affects the CRE behavior and the deformation in the fixed-fixed boundary condition is smaller than that in the fixed-free boundary condition.

  22. STABILITY OF SLOPES ON CLAYS OF VARIABLE STRENGTH BY LIMIT EQUILIBRIUM AND FINITE ELEMENT ANALYSIS METHODS Download Article

    Abdul Karim M. Zein and Waleed Abdel Karim
    • Article Type: Research Article
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    • Pages (157-164)
    • No of Download = 716

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    This paper presents an evaluation and comparative study on the stability analysis of simple slope models founded on undrained clay soils. The analysis was performed according to the limit equilibrium (LE) and finite element (FE) methods utilizing “Slide 2D” and “Plaxis 2D” computer programs respectively. Forty five slope models with different geometries based on soft, medium stiff and very stiff clay soil foundations were considered for stability analysis. The comparison made between four LE methods indicated that the Bishop and Spencer methods produced practically similar FOS results whereas the Fellenius and Janbu methods gave FOS values lower than the Spencer method by 3.0% and 7.4% respectively. For slopes founded on soft clays, the difference in FOS computed by the LE and FE methods is negligible but the FOS values computed by the LE methods were 8.5% higher than the FE method for slopes on medium and very stiff clays. Based on the results of linear regression analysis of all data, the Fellenius, Bishop, and Spencer methods gave FOS values higher than the FE method by 1.4, 5.3 and 5.7% respectively whereas the Janbu method gave FOS lower than the FE method by 4.3%. Evaluation of the effects of slope geometry and foundation soil properties on slope stability revealed a reliable relationship between FOS and a variable combining four slope and soil parameters.

  23. INTERNAL EROSION OF VOLCANIC COARSE GRAINED SOILS AND ITS EVALUATION Download Article

    Dao Minh Hieu, Shima Kawamura and Satoshi Matsumura
    • Article Type: Research Article
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    • Pages (165-172)
    • No of Download = 710

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    This paper aims at revealing mechanical behavior of volcanic coarse grained soils subjected to seepage flow. In order to accomplish the purposes, a series of upward seepage tests was conducted to grasp piping phenomenon in compacted volcanic soils and to investigate the effects of differences in compaction conditions on its behavior. In the experiments, the movement of soil particles in seepage flow tests was observed using an X-ray CT scanner in detail. The test results showed that destabilization of soil structures due to seepage flow is changed depending on an increase of amount of finer soil particles, and that internal erosion is induced by loss of fine particles with the changes in void ratio. As a result, a significant variation in hydraulic conductivity was generated. Additionally, internal stability of volcanic soils under several geotechnical conditions was elucidated by empirical criterion. In the consideration of the results, it was shown that volcanic coarse grained soil including pumice particles with a low specific gravity was internally unstable. Based on the results, a geotechnical evaluation was discussed for the stability of soil structures such as embankments constructed by volcanic coarse grained soils.

  24. ELECTROKINETIC PHENOMENA OF CATION EXCHANGE AND ITS EFFECT ON THE BEHAVIOUR OF EXPANSIVE CLAYS Download Article

    Nahesson Panjaitan and Ahmad Andi
    • Article Type: Research Article
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    • Pages (173-177)
    • No of Download = 488

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    This research is a series study of electrokinetic process that used as an alternative of stabilization effort of expansive clays. In particular, an observation of the behavioral changes of soil properties and also behavioral changes of soil swell that occur due to the phenomenon of cation exchange during the electrokinatic process were conducted. The cation used in this study was calcium ions (Ca2+) which are derived from the solution of lime which also used as a stabilizer. Electrokinetic test was conducted by using 2A and 25V DC power. The tested samples in this study were taken from three different locations in Central Java, namely: Purwodadi, Boyolali and Klaten. The composition and concentration of ions in expansive clays was tested by using AAS (Atomic Absorption Spectrum) method. Behavioral of soil properties known the limits of Atterberg (ASTM 4318 and ASTM 427) from testing while the swelling behavior of soil by testing of swelling (ASTM 4546). The observations against the behavior of clay expansive was at the condition of a change in the concentration of sodium ions (Na+) in the soil during the electrokinetic process. The results showed that at conditions of the concentration of sodium ions (Na+) was smaller than the initial concentration, the behavior of the value of the liquid limit (LL), the index plastic (PI) and the nature of the development of clay expansive indicated a downward trend, while the behavior of the boundary value shrinkage of the soil showed an upward trend. The results of this research can be used as a baseline data to the development of electrokinetic as an alternative effort of stabilization expansive clays.

  25. STRENGTH CHARACTERISTICS OF COMPACTED SOIL WITH PARTICULAR REFERENCE TO SOIL STRUCTURE AND ANISOTROPY Download Article

    Shunzo Kawajiri, Takayuki Kawaguchi, Shintaro Yamasaki, Dai Nakamura, Satoshi Yamashita and Satoru Shibuya
    • Article Type: Research Article
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    • Pages (178-185)
    • No of Download = 601

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    In this paper, the effects of compaction method on deformation and strength properties of a sandy soil were examined by means of triaxial and unconfined compression tests and bender element test. A X-ray CT scan was also employed for providing us with image of structure of two sandy soils (n.b., sample A and B). The undrained shear strength and dilatancy characteristics were seemingly affected by the compaction method employed, and also the aspect depended on the soil type. The Ghh/Gvh -value of sample A was larger than that of sample B. The result would mean that the Ghh/Gvh -value reflecting soil anisotropy is strongly related to the shear strength and dilatancy characteristics. In addition, the variation of pd and Dc of the statically compacted specimens is more significant than that of the dynamically compacted specimens. These variations in terms of pand Dc may also affect the deformation and strength characteristics.

  26. BEHAVIOUR OF PILE SUPPORTED WHARF IN LIQUEFIED SOILS Download Article

    Mohamed Faizur Rahaman Khazi and Mahammood Vazeer
    • Article Type: Research Article
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    • Pages (186-193)
    • No of Download = 603

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    A parametric study is carried out to study the performance of pile supported wharf structure under liquefying and lateral spreading soil conditions using nonlinear static pushover analysis. Displacement-based approach is adopted to study the soil pile interaction. Piles are modelled as beam elements and the parts of the piles embedded in soil are modelled as beams on Winkler foundation. The structure is modelled and analyzed using SAP2000. Pile yielding and hinge formation patterns in the piles during soil liquefaction and lateral spreading states are observed and compared with field observations. It is observed that when soil liquefied the base shear resistance dropped drastically and hence effected the performance of structure. Piles yielded at the interface of liquefied and non-liquefied layers when soil liquefied. It is also observed that the structure performed poorly when liquefied depth factor and slenderness ratio are increased. The method of analysis is simple and gives results confirming to the field observations and hence is an easy tool for assessment of existing port structures and preventing future disasters.