Articles

  1. EVALUATING THE RELATIONSHIP BETWEEN DYNAMIC SHEAR MODULUS AND NANO SCALE MODULUS OF ASPHALT BINDERS AT DIFFERENT AGING CONDITIONS Download Article

    Hasan M. Faisal, Umme A. Mannan, Rafiqul A. Tarefder and Md Arifuzzaman
    • Article Type: Research Article
    • View Abstract
    • Pages (1-7)
    • No of Download = 759

    Abstract

    close

    Traditionally, asphalt binder is characterized by a dynamic shear rheometer, which applies a shear load on a bulk volume of liquid asphalt binder to determine shear modulus (G*). Recently, a nanoindentation test​ can characterize an asphalt binder film in the form of a coating around roadway aggregates, which is more practical. In a nanoindentation test, a sharp tip is used to indent an asphalt film while residing on an aggregate surface to determine nanoindentation modulus (E). This study evaluates whether there is a relation between G* and E. For both tests, replicate samples were conditioned in three ways: unaged, rolling thin film oven aged, and pressure vessel aging. Results show that the E-value is approximately 2 to 6 times larger than the G*-value based on all samples/conditioning.​

  2. STRENGTH AND DEFORMATION CHARACTERISTICS OF EPS BEAD-MIXED SAND Download Article

    Agawit Thaothip and Warat Kongkitkul
    • Article Type: Research Article
    • View Abstract
    • Pages (8-15)
    • No of Download = 544

    Abstract

    close

    In this research, a study on strength and deformation characteristics of expanded polystyrene (EPS) bead-mixed sand was comprehensively conducted. A series of standard Proctor compaction tests were conducted to determine the proper amount water for use in the mixing between EPS bead and sand at the volumetric ratio of 1:1. A special series of drained triaxial compression tests were performed on the sand-EPS bead mixture (SEM) specimens. Various loading histories, consisting of: i) monotonic loading (ML) at different constant strain rates; ii) sustained (creep) loading (SL); iii) cyclic loading with small strain-amplitude (CL); and iv) stepwise changes in the strain rate during otherwise ML, were employed in this study. These loading histories were used to evaluate the elastic and viscous properties of the SEM. Then these properties were also compared with the ones obtained from the sand alone under similar loading conditions. It is found that the elastic and viscous properties of the SEM are qualitatively similar to those of sand alone. They are different in terms of quantity. A non-linear three-component (NTC) model was used to simulate the elasto-viscoplastic deformations of the SEM. The simulations are well successful by using the model parameters determined especially for the SEM sand under the conventional model framework.​​

  3. INFLUENCE OF PULLING OUT EXISTING PILES ON THE SURROUNDING GROUND Download Article

    Shinya Inazumi, Tsutomu Namikawa, Shuichi Kuwahara and Shin-ichi Hamaguchi
    • Article Type: Research Article
    • View Abstract
    • Pages (16-21)
    • No of Download = 487

    Abstract

    close

    Teardowns of social infrastructure, including civil structures, have been increasing in number in recent years because these structures have aged and their utilization has decreased along with the decrease in population. The number pile foundations being pulled out is now far greater than that being newly installed. However, after a pile foundation is pulled out, the mechanical characteristics of the surrounding ground may be affected by the existence of the resulting hole formed by pulling out. There are no regulations yet on injecting fillers into pull-out holes, and the influence of filler strength on the surrounding ground is yet to be elucidated. This study considers the influence of a pull-out hole on the static and dynamic characteristics of the surrounding ground using two-dimensional dynamic finite-element analysis. The special qualities required by fillers injected into such holes are also clarified.

  4. GEOTECHNICAL REQUIREMENTS FOR CAPTURING CO2 THROUGH HIGHWAYS LAND Download Article

    M. Ehsan Jorat, Ben W. Kolosz, Mark A. Goddard, Saran P. Sohi, Nurten Akgun, Dilum Dissanayake and David A.C. Manning
    • Article Type: Research Article
    • View Abstract
    • Pages (22-27)
    • No of Download = 510

    Abstract

    close

    Roadside verges in Britain support 238,000 hectares of vegetated land and approximately 10
    hectares of vegetated central reserves. These areas have the potential to be engineered in such a way that they
    deliver a range of ecosystem services including flood regulation and biodiversity conservation in addition to their
    primary functions such as comfort of sidewalk users (mostly un-vegetated), protection of spray from passing
    vehicles, a space for benches, bus shelters, street lights and other public amenities, and visual improvement of the
    roads and designated green belts. Previous research has shown that in soils, calcium-rich materials such as recycled
    crushed concrete or natural crushed dolerite undergo carbonation. This effectively captures CO2 from the atmosphere and stores it in the form of CaCO3 precipitated between soil particles. Engineering this process can potentially assist the UK in achieving its ambitious target to reduce CO2 emissions by 80% of 1990 levels by 2050. Rates of carbonation measured at urban brownfield sites in the UK suggest that treating 12,000 hectares of land containing suitable amendments could remove 1 million tonne CO2 annually. However, brownfield sites are often subjected to re-construction activities which would reduce the rate of CO2 absorption from the atmosphere by sealing. To optimize the rate of carbonation, engineered soils need to be constructed at locations subjected to least post-construction activities and roadside verges and central reserves represent a key opportunity in this regard. This paper calculates limits to CaCO3 formation within the first 1 m of pore spaces of soils at roadside verges and central reserves in Britain considering a soil porosity of 20%.

  5. DRAINED SHEAR STRENGTH OF COMPACTED KHON KAEN LOESS Download Article

    R Nuntasarn and W. Wannakul
    • Article Type: Research Article
    • View Abstract
    • Pages (28-33)
    • No of Download = 501

    Abstract

    close

    The objective of this study was to determine the relationship between drained shear strength and matric suction of compacted Khon Kaen loess. Khon Kaen loess in this study was compacted at 95% by modified method. This soil sample was investigated a soil water characteristic curve (SWCC) from the pressure plate test. Moreover the relationship between drained shear strength and matric suction was determined from the consolidated drained triaxial test (CD Test) under saturated and unsaturated condition. Three saturated specimens were tested to determine an effective friction angle (φ´) and an effective cohesion (c´). Another three unsaturated specimens were tested with various matric suction of 30, 180 and 280 kPa, respectively. The net confining pressures of these specimens were constant at 100 kPa. To determined drained shear strength at unsaturated condition, an effective friction angle (φ´) was assumed to be constant with a matric suction value. The SWCC of compacted Khon Kaen loess showed a bimodal curve. The first air-entry value and the first residual volumetric moisture content was 4 kPa and 20%, respectively. The results of saturated consolidated drained triaxial test (CD Test) presented that an effective friction angle (φ´) and an effective cohesion (c´) was 31 degree and 54 kPa, respectively. Moreover the unsaturated triaxial test showed a linear relationship between drained shear strength and matric suction with the φb angle of 28 degree.

  6. UTILIZATION OF TOFU LIQUID WASTE GENERATED FROM ANAEROBIC PROCESSING IN COMPOST PREPARATION Download Article

    M. Faisal
    • Article Type: Research Article
    • View Abstract
    • Pages (34-39)
    • No of Download = 705

    Abstract

    close

    This study aims to identify the ability of tofu liquid waste generated from anaerobic processing to act as a microorganism source to help expedite compost decomposition. In this research, composting was performed on 2 kg of rice husks to which tofu liquid waste was added in various volumes (500–2000 mL) and 1 kg of cow manure. This research used a nonfactorial completely randomized design with five treatments and four repetitions, which made a total of 20 unit trials. Changes in pH, humidity (rH), C composition, N, C/N ratio, and number of colonies were analyzed to observe the compost quality. The data collected were then analyzed using SPSS 16. The research findings showed that increasing the volume of tofu liquid waste has a significant impact on composting temperature, and all compost outputs were within proper compost criteria. Increasing tofu waste volume can improve the population of microorganisms, which accelerated the decomposition process of organic matter. The highest number of bacterial colonies, 73 colony forming units, was found on 1500-mL treatment. At this condition the values obtained were 17.94%, 0.9%, and 20.1 for C, N, and C/N ratio, respectively.

  7. EVALUATION OF DIFFERENT FIBER REINFORCED MORTAR AS RETROFITTING MATERIALS FOR RC COLUMNS Download Article

    Bernardo A. Lejano
    • Article Type: Research Article
    • View Abstract
    • Pages (40-47)
    • No of Download = 547

    Abstract

    close

    This study is about the use of fiber reinforced mortar (FRM) as a jacketing material for reinforced concrete (RC) columns. Presented in this paper are analyses of the test results of destructive-loading that were conducted to explore the applicability of different jacketing materials as retrofit to RC columns. The jackets used to wrap RC columns were built of mortar mixed with different fibers. The fibers considered were steel fibers and polymer fibers. A simple model based on material properties was used to simulate the axial strength of the columns. The numerical model calculation results as well as the experimental test results were used to assess the performance of the jacketing materials used. The experimental part consisted of testing two sets of column specimens. The first set is wrapped with mortar jackets reinforced with steel fibers and the second set is wrapped with mortar jackets reinforced with polymer fibers with and without fly ash. The efficacy of the different FRM jackets as retrofitting materials was assessed by calculating the effect of confinement. The calculation was accomplished by measuring the maximum load of the retrofitted columns with jackets and then subtracting the load that can be carried by the control specimens, that is, the column with the original cross section. The confining effect was used as the basis in determining the confined compressive strength of concrete and then used to establish a model that can simulate the axial strength of the columns. The results indicate that the FRM jackets are effective as retrofitting material for RC column.

  8. THE EXPERIMENTAL DESIGN AND CARBON FOOTPRINT ASSESSMENT OF NON-GLAZED FLOOR TILES Download Article

    Karin Kandananond
    • Article Type: Research Article
    • View Abstract
    • Pages (48-53)
    • No of Download = 529

    Abstract

    close

    Carbon emission from the manufacturing sector is a critical issue which is concerned by the environmental authorities since the violation of the carbon emission cap might lead to the sanction by one of Thailand's largest trade partner, European Union (EU). As a result, it is important for the manufacturers to be able to assess their own products' carbon footprint. In this study, the selected case study is a ceramic factory which manufactures non-glazed floor files. The scope of evaluation covers Business-to-Customer (B2C) transaction while the life cycle of a product includes four stages, i.e., resource extraction, manufacturing, distribution, use and waste disposal. The study results indicate that the highest contribution to the carbon emission is from the extraction of ceramic clay while the manufacturing stage has the second highest effect on the emission. The distribution of products, use and disposal are the life cycle stages which have small effects on the emission. Another objective of this research is to conduct an empirical study which leads to the capability to quantify the effect of different factors on the manufacturing of floor tiles. According to the experimental study, three factors, i.e., chalk clay, ball clay and feldspar, are considered as the process inputs while the response variables are percent absorption and hardness. Elaborately, 23 full factorial design was deployed to study the find the relationship between inputs and outputs. The results has two folds. The first fold is useful for the manufacturers who would like to understand how much their product has emitted the greenhouse gas to the atmosphere and it might lead to the minimization of their emission. Moreover, the relation between the tile characteristic and factors affecting the manufacturing is known so the manufacturer is able to efficiently optimize the manufacturing process in order to achieve the highest quality products.

  9. INFLUENCE OF CLAYSTONE DETERIORATION ON SHEAR STRENGTH OF BACKFILL Download Article

    Pisut Rodvinij and Pitiwat Wattanachai
    • Article Type: Research Article
    • View Abstract
    • Pages (54-59)
    • No of Download = 584

    Abstract

    close

    Claystone in Mae Moh mine after excavation has been used as a backfill material to counterweight instability slope. However, claystone deteriorates when it has been exposed to wet-dry process in the natural condition. The investigation on the properties of claystone under natural condition and control condition can clarify the deterioration effect due to wet-dry process. Deterioration can be defined as the alteration process on size distribution and strength of claystone. Sieve analysis test and unconfined compression test were conducted on claystone samples to investigate the deterioration effect on size distribution and strength of claystone. Claystone exposed to natural condition having a decrease of an average particle size (D50) to be approximately 50 mm in 12 weeks and unconfined compressive strength of claystone was decreased 45% in 3 weeks. In contrast, claystone under control condition gave the same size distribution and unconfined compressive strength slightly decreased. Thus, the result demonstrated wet-dry process in natural condition was the main cause of claystone deterioration. The decrease on size distribution of claystone due to deterioration can be the cause of reduced on backfill shear strength. In order to clarify this assumption, direct shear test was conducted on 3 different particle sizes of claystone to simulate the effect of size reduction on shear strength of backfill. The experimental results demonstrated shear strength of the larger particle size samples was higher than the smaller especially under high

  10. EARTHQUAKE ATTENUATION MODELS AND ITS RESPONSES TO EARTH ZONE DAM IN UPPER NORTHERN PART OF THAILAND Download Article

    Tawatchai Tanchaisawat, Sirikanya Laosuwan and Nutapong Hirano
    • Article Type: Research Article
    • View Abstract
    • Pages (60-65)
    • No of Download = 574

    Abstract

    close

    The upper northern part of Thailand is mountainous area which classified as moderate risk by earthquake. This study was focused on the earthquake attenuation model of Abrahamson and Silva (2008). Exciting quake source from the Chiang Rai 2014 earthquake was recorded at earth zone dam site study. The accelerometer was installed in the bottom of dam which is 59 m height, 9 m width and 1,950 m length. The attenuation model is the relationship between acceleration, distance, size of earthquake, period of stabilization, characteristics of seismic sources and geological conditions. This research aims to compare the peak ground acceleration (PGA) between the attenuation models and the data measurement at the dam to check the accuracy of the model. And to study the dynamics analysis in the dam by using two selected time history records with different wave characteristics as: short period (EQ1) and long period (EQ2) to analyze the behavior of the pore water pressure, the stress and displacement in the dam. The results of this study revealed that the Peak Ground Acceleration (PGA) from the attenuation model of Abrahamson and Silva equal to 0.017787 g. And the percentage error of calculated PGA when compared to the PGA from measurement was 6.38. The analysis of the dynamics by using seismic waves with different time duration. EQ1 have made the pore water pressure on the dam higher when the effective stress in the dam decrease, which makes the displacement of the dam more than EQ2.

  11. PROPERTIES OF SOIL-CEMENT BLOCKS MANUFACTURED USING PRODUCED WATER FROM OIL FIELDS: A PRELIMNARY INVESTIGATION Download Article

    Khalifa S. Al-Jabri, A. W. Hago, Mahad Baawain and Gyanendra Sthapit
    • Article Type: Research Article
    • View Abstract
    • Pages (66-72)
    • No of Download = 537

    Abstract

    close

    One of the prime aims of the sustainable development strategies in many countries is to provide safe and secure environment for their inhabitants. This goal can be achieved through the use of environmental friendly building materials, commonly referred to as green building materials and the effective use of waste materials in useful applications such as construction industry. In Oman, saving the environment by finding alternative useful methods for re-using different kind of wastes and seeking ways to reduce the emission of harmful gases, and looking for affordable low-income housing for people are of great concern to the authorities in order to preserve and sustain the environment for the future generations. In order to fulfill such objective, research into the use sustainable materials in the construction industry is encouraged. Therefore, in the same context, this paper discusses the preliminary results from an ongoing research study on the use of produced water from the Petroleum Development Oman (PDO) Nimr and Marmoul oil-fields in the development of a new soil-cement block which possesses good strength, good thermal insulation and consume lower quantity of cement than the conventional one. Soil and water samples were brought from Marmoul and Nimr sites. The initial results indicated that both soil and water are suitable for production of compressed blocks with good mechanical properties.

  12. EXTRATING METHOD OF DEFORMED PART BY MICROTREMOR ON STONE WALLS OF JAPANESE TRADITIONAL CASTLE Download Article

    Minoru Yamanaka, Hayato Ishigaki, Katsuhiko Koizumi, Shuichi Hasegawa and Hiroyuki Araki
    • Article Type: Research Article
    • View Abstract
    • Pages (73-79)
    • No of Download = 412

    Abstract

    close

    The non-destructive survey technique is required to estimate quantitatively the deterioration
    level of a stone wall at a traditional castle site. Microtremor measurement method is one of the nondestructive survey technique to estimate geotechnical characteristics of the ground. In this study, microtremors are measured at the stone wall of the Marugame castle, in order to evaluate vibration characteristics of deformed or non-deformed stone wall; the method to extract the deformation part of the stone wall is discussed based on the measurement results. The results showed that the value of H/V and H/H spectral ration increased with the increase of deformation of wall but also by the elevation of a measurement point. It was observed that the values of energy ratio were scattered widely. It is concluded that the H/H spectral ratio is a suitable index to indicated the deformation level of a stone wall. By setting the adequate threshold value, deformed walls were extracted roughly by the value of H/H spectral ratio at the Marugame castle.

  13. DAMAGE QUANTIFICATION OF BEAMS USING FREQUENCY SIGNATURE Download Article

    Bryan Josef T. Medrano and Lessandro Estelito O. Garciano, D. Eng
    • Article Type: Research Article
    • View Abstract
    • Pages (80-86)
    • No of Download = 539

    Abstract

    close

    A rapid method for determining the damage severity sustained by a beam proved to be challenging due to either limited studies conducted on the subject or alternative methods require highly sophisticated and costly equipment to perform. In this research, the unique frequency signature emitted by a beam when excited by an external force was utilized in order to determine the changes in the properties of the beam. Experiments were performed using a roving accelerometer hammer impact test on a beam with a grounded configuration to test the changes occurring as the controlled damage sustained by the beam increases. The acceleration response of the beam obtained from the experiment is then processed using software incorporating Kalman Filter and structural dynamics. Results show that the dominant frequency obtained in both the Fast Fourier Transform and Power Spectral Density of the acceleration response of the beam decreases as the damage incurred by the beam increases. The results also show that regardless of the position of the accelerometer, dominant frequencies tend to converge to a value depending on the damage sustained in the beam. Damping ratio of the beam also decreased as the damage sustained by the beam increased. Inversely, the increase in damage of the beam corresponds to an increase in the dissipation rate of the beam. The study was able to achieve its goal of quantifying damage in a beam through the use of frequency signature by identifying the changes in its dominant frequencies and the damping ratio and dissipation rate.

  14. MODELLING OF CARBONATION OF REINFORCED CONCRETE STRUCTURES IN INTRAMUROS, MANILA USING ARTIFICIAL NEURAL NETWORK Download Article

    Richard M. De Jesus, Joshua A. M. Collado, Jemison L. Go, Mike A. Rosanto, and John L. Tan
    • Article Type: Research Article
    • View Abstract
    • Pages (87-92)
    • No of Download = 626

    Abstract

    close

    Corrosion is a perennial problem in reinforced concrete structures, and is a serious concern due to the deterioration that it causes to reinforced concrete members. Though regarded as having a minor influence to corrosion compared to chloride-induced corrosion, carbonation is becoming a serious threat due to continuous development of cities like Manila. Expectedly, as Manila continues to develop, carbon emission shoots up to alarming proportions, calling out for studies to investigate and mitigate its effect to human health and structures. Artificial Neural Network (ANN) is known for establishing relationships among parameters with unknown dependency towards another variable, similar to the case of carbonation’s dependency with age, temperature, relative humidity, and moisture content. Utilizing field-gathered secondary data as training and testing parameter for back propagation algorithm, an ANN model is proposed. Prediction of carbonation depth using ANN Model C421 showed reliable results. Validation of performance of Model C421 was further checked by comparing its prediction with a different set of field-gathered secondary data and results confirmed good agreement between prediction and measured values

  15. MATHEMATICAL MODELING OF FOREST FIRES INITIATION, SPREAD AND IMPACT ON ENVIRONMENT Download Article

    Valeriy Perminov and Alexander Goudov
    • Article Type: Research Article
    • View Abstract
    • Pages (93-99)
    • No of Download = 433

    Abstract

    close

    A mathematical model of surface and crown forest fires spread and impact is considered. A three-dimensional multiphase, physic based model is used. The boundary-value problem is solved numerically by finite volume method. This model has been applied to describe the process of initiation and spread of surfaces forest fires and their transfer into crown of forest fires. The results of numerical solutions present the distribution of the main functions of the process (the velocity field, the temperature of gas and solid phase, the concentration of the oxygen, gas product of pyrolysis and inert components, etc.) over time. Scenarios modeled within this study represent a possible approach to the preliminary assessment of risk and should be verified by more detailed computational fluid dynamic (CFD) modeling.

  16. ARCHAEOLOGICAL OBJECTS AS ELEMENTS OF INFORMATIONAL LIFE SUPPORT SYSTEM AND SOURCES OF INFORMATION ABOUT THE EVOLUTION OF THE ENVIRONMENT Download Article

    Alina Paranina
    • Article Type: Research Article
    • View Abstract
    • Pages (100-107)
    • No of Download = 376

    Abstract

    close

    The article shows the objective criteria of sacralization of objects of natural and cultural heritage of Eastern Europe and Southern Siberia, based on the performance of informational function in ancient human life-support system (as instruments of navigation in space-time). Transformation of functions of sacral objects from their inception to the beginning of the third millennium, due to the development of geo-cultural space (changes in technology, socio-cultural paradigm and social and economic conditions). The stages of the evolution of navigation technologies, selected by the author on the basis of cultural layering of archaeological objects are reviewed in the article. The carried-out retrospective analysis allows to make the assumption that improvement of technologies of orientation could be a basis of emergence and development of Homo sapiens (sapientation): astronomical supervision in horizon observatory develops a system of ecological thinking; supervision over a shadow of the gnomon tool develops abstract thinking (the abstract graphic sign is genetically connected with concrete natural process).

  17. INVESTIGATION OF POTENTIAL ALKALI-SILICA REACTIVITY OF AGGREGATE SOURCES IN THAILAND Download Article

    Suvimol Sujjavanich, Krit Won-In, Thanawat Meesak, Watcharagon Wongkamjan and Viggo Jensen
    • Article Type: Research Article
    • View Abstract
    • Pages (108-113)
    • No of Download = 581

    Abstract

    close

    Since the first local evidence of alkali-silica reaction (ASR) was reported in Thailand in 2011,
    awareness of ASR was raised and the importance of aggregate performance database was recognized, thus an
    attempt to set up local aggregate database was initiated. As part of the effort to establish the database, a study
    of potential ASR reactivities was carried out involving aggregates from several current industrial sources in
    eastern and central Thailand and the results were presented here. Aggregate samples were randomly collected
    from various sources and tested by two methods; accelerated mortar-bar test (AMBT) and petrographic examination. The types of aggregate sampled included limestone, greywacke, and rhyolitic tuff. The AMBT expansion results indicated that several aggregate types had larger expansion than the threshold of potentially deleterious ASR behavior as suggested by ASTM C 1260 standard. Furthermore, it was found that samples of same aggregate type, although apparently had mineralogically similar compositions, had different reactivities, particularly when sampled from around geological fault zone compared with that taken from the surrounding area and portions of parent rock were observed to be weathered in this area. Thin section analysis revealed evidence of ASR gel at the aggregates’ rim, inside the aggregates and in the matrix. These findings suggest possible future ASR problems in Thailand as well as in neighboring countries where the continuity of geology pattern is observed.

  18. COMPARATIVE ANALYSIS OF NEW GEOMATERIALS AND EMBANKMENT CONSTRUCTION METHODS CONSIDERING RECYCLING Download Article

    Hideyuki Ito, Koichi Yamanaka, Hideo Noguchi, Takahiro Fujii and Kunio Minegishi
    • Article Type: Research Article
    • View Abstract
    • Pages (114-119)
    • No of Download = 580

    Abstract

    close

    The cutting and embankment construction method may cause grand subsidence or landside at a location with soft ground or risk of landsides. A construction method employing a new composite geomaterial using expanded polystyrene is effective for construction at such a location because of its light weight and workability. However, there is not much research reported on the use such new materials with examples of constructions using these materials. This study aimed to understand the problems associated with the use of the new geomaterials and determine how they can be improved by analyzing various environmental loads and life cycle costs that in various embankment construction methods in consideration of whether new geomaterials are used and waste materials are recycled. Four different methods were compared with respect to their environmental impact and cost. The research demonstrated the possibility of reducing environmental loads and life cycle costs by employing recycling in various embankment constructions methods.

  19. 3D NUMERICAL MODEL IN NONLINEAR ANALYSIS OF THE INTERACTION BETWEEN SUBSOIL AND SFCR SLAB Download Article

    Jana LABUDKOVA and Radim CAJKA
    • Article Type: Research Article
    • View Abstract
    • Pages (120-127)
    • No of Download = 662

    Abstract

    close

    For decades attention has been paid to interaction of foundation structures and subsoil and, in turn, to development of interaction models. Complexity of a static solution is given mainly by selection of a computational model, effects of physical-nonlinear behaviour of such structure and co-effects of the upper structure and the foundation structure. ). Input data for numerical analysis were observed experimental loading test of steel-fibre reinforced concrete slab. The loading was performed using unique experimental equipment which was constructed in the area Faculty of Civil Engineering, VŠB-TU Ostrava. Homogeneous half-space this takes no account and calculated settlement is strongly dependent on the size of the subsoil model, as parametric study demonstrated. The modulus of deformability changes continuously, depending on the depth, in the inhomogeneous half-space. Values calculated by 3D numerical model were compared with values measured during the loading test of steel-fibre concrete slab.

  20. EXPERIMENTALLY MEASUREMENT AND ANALYSIS OF STRESS UNDER FOUNDATION SLAB Download Article

    Marek MOHYLA, Karel VOJTASIK, Martin STOLARIK, Miroslav PINKA and Hynek LAHUTA
    • Article Type: Research Article
    • View Abstract
    • Pages (128-135)
    • No of Download = 649

    Abstract

    close

    Understanding of a load redistribution into subsoil below building foundation is an important knowledge for reliable design and its economy too. The article presents the results of a physical model of a foundation slab and its interaction with the subsoil. The interactions were investigated comprehensively by monitoring the developments of stress in the subsoil and foundation slab settlement during its loading. The load acting on the foundation was applied by strutting the hydraulic press against heavy steel frame which was established by the Department of Building Structures, Faculty of Civil Engineering of VSB -TU Ostrava for this purpose. The preparatory phase of the present experiment involved the homogenization of soil during which trio pressure cells in three horizons were gradually fitted. The quality of homogenization was checked on an ongoing basis through field tests: dynamic penetration load test, dynamic plate load test and seismic measurement of foundation slab response. Finally, the homogenized soil was subjected to mechanical analysis to determine the strength and deformation parameters for basic Mohr-Coulomb constitutive model.

  21. GENETIC DIVERSITY AND GENETIC STRUCTURE OF AN ENDANGERED SPECIES, ERIOCAULON NUDICUSPE, GROWING IN ARTIFICAL DISTURBING HABITATS Download Article

    Michiko Masuda, Tadamasa Fukagawa and Fumitake Nishimura
    • Article Type: Research Article
    • View Abstract
    • Pages (136-143)
    • No of Download = 648

    Abstract

    close

    Eriocaulon nudicuspe (Eriocauloaceae) is an endangered species in Japan. Habitats of the species are lost by city development. So many conservation areas are established in Aichi Prefecture, and protection activities are done by many natural protecting groups, and the extinction rate in recent years is being decelerated. But many protecting groups often transplanted from some other places, and genetic disturbance was a problem. We sampled 12 populations of the species from nature reserved areas, and studied them for allelic variation at 17 enzyme loci. There was no significant correlation between the real distance of conserved areas and genetic distances, suggesting that the gene disturbances occurred in these areas especially in frequently managed areas. On the other hand, the degree of the genetic differentiation at strictly conserved area where conservation management is done only once a year was high and there was no evidence about genetic disturbances. There was a possibility peculiar genetic disappearance of each habitat for genetic disturbance, and the necessity with which a guideline of protection activity is made was indicated.

  22. NUMERICAL MODELING OF CENTRIFUGE TEST PROCEDURE FOR DIFFERENT EMBANKMENT CASES Download Article

    Ali Sobhanmanesh, Ramli Nazir, Tan Choy Soon and Deprizon Syamsunur
    • Article Type: Research Article
    • View Abstract
    • Pages (144-150)
    • No of Download = 755

    Abstract

    close

    Physical modelling through full-scale and small-scale models is widely implemented in order to define specific aspects of the prototype behaviour. On the other hand, numerical modeling is essentially required to cope with the complex geotechnical problems due to the ability of considering and analyzing all aspects of the model and can afford more perception about the behavior of structures such as geosynthetic-reinforced embankments. In this study, four different cases of unreinforced and reinforced embankment models constructed on soft and stiff grounds were studied. Small-scale physical modelling by means of centrifuge tests and numerical modelling by means of finite element simulations were performed. As the small-scale model was rotated in different acceleration fields during the centrifuge test, the dimensions of the centrifugal model were different from the original state of the prototype in different stages of the test. This paper focused on developing a finite element simulation based on the dimensions of a centrifugal model in different incremental acceleration fields applied during the stages of the test. Comparing the results of finite element simulations with the measurements of the centrifuge tests showed a good agreement between the two methods, which verified the reasonableness of the finite element models in analysis of embankments based on small-scale centrifugal dimensions. Moreover, the results showed the different deformation behaviour for embankments on soft and stiff grounds and indicated the significant effect of the geosyntheic reinforcement on increasing the stability of the embankment on soft ground.

  23. FIELD PERFORMANCE OF TRANSITION RIGID PILED EMBANKMENT WITH SURCHARGED VERTICAL DRAIN OVER SOFT GROUND Download Article

    Ramli Nazir, Hossein Moayedi, Puspanathan Subramaniam and See-Sew Gue
    • Article Type: Research Article
    • View Abstract
    • Pages (151-155)
    • No of Download = 585

    Abstract

    close

    Commonly, thick filling works over soft clay is aided with piled embankment at bridge approach to reduce differential settlement between the piled abutment and embankment over soft ground. However, long stretched thick filling works over soft ground requires substantial resources and time to construct rigid piled embankment. Generally for such long stretched and thick filling development over soft ground, other ground treatment such as prefabricated vertical drain (PVD) with surcharge is introduce to reduce the cost of construction. However, excessive total and differential settlement at the surcharged prefabricated vertical drain (SPVD) and rigid piled embankment intersection during post construction period may leads to rectification works over the time. This paper presents the field performance of an alternative design approach for long stretched thick filled embankment over soft clay at structure approach to control the differential settlement between the two conventional ground treatment approaches. With the introduction of the alternative ground treatment approach at the intersection of the two conventional ground treatment, post construction total settlement and differential settlement is reduced significantly.

  24. ANALYSIS OF EXTREME RAINFALL-INDUCED SLOPE FAILURE USING A RAINFALL INFILTRATION-INFINITE SLOPE ANALYSIS MODEL Download Article

    Thapthai Chaithong
    • Article Type: Research Article
    • View Abstract
    • Pages (156-165)
    • No of Download = 578

    Abstract

    close

    The aim of this paper is to propose the method for analyzing the slope response to rainfall infiltration during the extreme rainfall in a mountainous area by combining Green-Ampt infiltration model and infinite slope analysis model. The Green-Ampt infiltration model is used to calculate cumulative infiltration into the soil slope. The infinite slope analysis model is chosen to represent the shallow soil slope failure and the simplified first order second moment (SFOSM) is used to calculate the probability of failure. The reliability of the proposed model is validated using three landslide history cases in southern Thailand. Considering the result of calculation, it was found that the proposed model can be used the estimating the soil slope failure occurrence time.

  25. FATIGUE RESISTANCE OF SURFACE TEMPERATURE REDUCING PAVEMENT UNDER FIXED-POINT LOAD Download Article

    Hiroshi Higashiyama and Masanori Sano
    • Article Type: Research Article
    • View Abstract
    • Pages (166-173)
    • No of Download = 609

    Abstract

    close

    Asphalt and concrete pavements cover a high percentage of urban area. In the summer season, the surface temperature of asphalt pavements exposed to the solar radiation increases to 60°C or more. This is one cause of the urban heat island phenomenon. In the field of road engineering, cool pavements have been constructed to decrease the surface temperature and to improve the road environment. We have previously studied the cement-based grouting material containing cement, ceramic waste powder, and natural zeolite for cool pavements. This cool material is poured into voids in porous asphalt pavements. The construction method for this cool pavement is the same as that for water retaining pavements. The temperature measurements show that the surface temperature was lower by 15-20°C than the conventional porous asphalt pavement temperature of 60°C. On the other hand, the accumulation of permanent strain in the asphalt pavements causes rutting under passing traffic loads in the hot summer season. In this study, the fatigue tests under a fixed-point load were conducted to evaluate the fatigue resistance of the surface temperature reducing pavement at 40°C. The fatigue resistance of pavements under various loading levels is evaluated at sinking displacements of 15 and 20 mm. The test results show that the surface temperature reducing pavement has a higher fatigue resistance than conventional porous asphalt pavements.

  26. EVALUATION OF SOIL REINFORCED WITH GEOGRID IN SUBGRADE LAYER USING FINITE ELEMENT TECHNIQUES Download Article

    Saad Farhan Ibrahim AlAbdullah and Noor Sabah Taresh
    • Article Type: Research Article
    • View Abstract
    • Pages (174-179)
    • No of Download = 791

    Abstract

    close

    The paper describes Finite Element (FE) models that are used to simulate the behavior of two types of geogrid laid between subbase/subgrade layers in flexible pavement structure. The properties of materials used to predict behavior of the sand soil is required to give accurate predictions of pavement performance. Physical and Mechanical properties of the pavement structure components of are established using standard laboratory tests including repeated load test with geogrid reinforcement. The results of analyses show that the finite element model results and implementation reported in this study can accurately predict permanent deformation in the pavement structure.

  27. UNDRAINED SHEAR STRENGTH OF LOW DOSAGE CEMENT-SOLIDIFIED DREDGED MARINE SOILS (DMS) FOR RECLAMATION WORKS Download Article

    Nurul Syakeera Nordin and Chee-Ming Chan
    • Article Type: Research Article
    • View Abstract
    • Pages (180-186)
    • No of Download = 652

    Abstract

    close

    The disposal of dredged marine soils (DMS) into the ocean or on land are unsatisfactory in managing its large quantity which indicates a high demand on new ocean and land disposal. DMS are classified as contaminated waste that contain of organic matter and heavy metals. Contaminated DMS can harm aquatic organism, animals and human. It must be disposed safely to ensure the contaminants are not released. By reusing the DMS as geomaterial or fill for reclamation works, it will minimize the impact to environment. The treatment techniques towards DMS are an essential and necessary in enhancing its engineering properties and assuring the effectiveness for a long-term solution. This paper presents a preliminary study in solidifying the Kuala Perlis DMS (3.4 LL) with lowest dosage of cement (1 – 10 %) at different curing period (3, 7, 14 and 28 days). It shows the undrained shear strength (cu) value of cement-solidified were increased compare to the raw DMS. The results for cement dosage above 7 % shows a good improvement in cu value and the strength development were found increased after 3 days of curing. It was explained that the lowest water-cement (w/c) ratio tend to have a higher cu value of the cement-solidified DMS.