Now showing 1 - 10 of 53
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    Inspection of bridge failure during construction: A case study of a bridge over a drainage canal
    (2025-04-01)
    Suksawat, Taweephong
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    Ayawanna, Jiratchaya
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    Nghia-Nguyen, Trong
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    Meetorranee, Thawidej
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    Promthong, Boonchom
    This paper presents a case study of a bridge failure during construction in an infrastructure development project in Nakhon Si Thammarat, Thailand. This highlights the critical role of thorough inspection and early detection of structural failures. The failure, related to foundation-related issues, shows how even minor errors in the construction sequence can lead to significant structural problems. Key steps for evaluating foundation failures are assessing the structure's movement and utilizing an inclinometer to determine ongoing failure. Resistivity surveys, in conjunction with screw driving sounding tests (SDS), were performed to assess soil properties, while the finite element method (FEM) was applied to validate the observed failure behavior. The results show that an inclinometer effectively monitored these structures’ movement. The resistivity surveys proved useful in identifying soil layers in the wide area. Meanwhile, the SDS tests were able to determine the soil's undrained shear strength. FEM simulations provided valuable insights into the behavior of underground structures. Consequently, comprehensive inspections are essential to mitigate foundation failure risks and ensure critical structures’ safety and longevity.
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    Integrating Multiple Linear Regression Analysis and Machine Learning Models to Predict the Bearing Capacity of Strip Footings on Sandy Clay Slopes
    (2025-02-01)
    Mase, Lindung Zalbuin
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    Misliniyati, Rena
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    Muharama, Nia Afriantialina
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    Supriani, Fepy
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    Ahmad, Debby Ariansyah
    This paper presents Multiple Linear and Machine Learning models of bearing capacity for strip footings at sandy clay slopes subjected to vertical loads. Several parameters are considered in the analysis, including footing width, embedment depth, unit weight, slope angle, internal friction angle, and soil cohesion. A finite element analysis is conducted to assess the impact of these factors. Additionally, an empirical prediction for bearing capacity is proposed. Machine learning techniques utilising various models are employed to analyse performance outcomes, with the Shapley Additive Explanations (SHAP) method used to quantify the contribution of each parameter. The results show that the empirical formulation for predicting ultimate bearing capacity can be effectively applied in engineering practice. Significantly, the findings indicate that the XGBoost model yields the most precise predictions of bearing capacity. The primary parameters influencing bearing capacity include embedded depth, width, unit weight, and internal friction angle, whereas vertical load and unit weight have a minimal impact.
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    Optimizing Silica Fume Admixture for Enhanced Strength of Soil–Cement Columns
    (2025-10-01)
    Huan, Vo Nguyen Phu
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    Nguyen, Trong Nghia
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    The Deep Soil Mixing (DSM) method is effective for rapid soil stabilization. In contrast, it presents challenges when applied to expansive and problematic soils, as well as in environments with high salinity. This study investigates the incorporation of silica fume as an admixture to enhance the unconfined compressive strength (UCS) of soil–cement columns using the DSM construction method. Soil–cement specimens were prepared with silica fume-to-cement ratios of 0%, 1%, 3%, and 5% and cured under varied conditions, including untreated natural soil, tap water, and saline solutions with 2.5% and 5% NaCl concentrations. UCS tests conducted on 7, 14, 28, and 60 days revealed that a 1% silica fume dosage optimally enhances strength across all curing environments, with soil-based curing achieving the highest performance. The improvement is attributed to the formation of calcium silicate hydrate (C–S–H), which enhances the UCS of the specimens. However, higher silica fume contents led to reduced efficiency due to particle agglomeration and reduced hydration reaction. By addressing the challenges of traditional DSM applications, this study demonstrates the potential of silica fume to improve the performance and durability of soil–cement columns, offering a sustainable and practical approach for geotechnical engineering in diverse and challenging environments.
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    Mitigations of flooding and soil erosions geo-disasters in Thailand and Laos due to climate change: From Mountains to Lowlands
    (2017-06-01)
    Bergado, D. T.
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    Voottipruex, P.
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    Hino, T.
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    Chanmee, N.
    In 2011, Thailand has suffered from devastating flooding due to climate change. During this time, 2 typhoons from the Pacific area went straight across Vietnam to Northern Laos and Northern Thailand instead of the usual path to Taiwan and Japan. Subsequently, huge flooding damaged many infrastructures and overtopped flood protection dikes of many industrial estates and educational institutions in the Central Plain of Thailand such as at Hi-Tech Industrial Estate, Bang Pain Industrial Estate. Navanakom Industrial Estate and Asian Institute of Technology, to name a few. The same phenomenon also occurred in neighboring Laos PDR which caused unusually heavy rains and widespread river flooding. Consequently, riverbank erosions accompanied by slope failures occurred at Xedon River in Pakse, Southern Laos due to saturation caused by high water levels accompanied by high velocity flow of the flooded river. To evaluate the stability of these mitigation structures, finite element and limit equilibrium methods were utilized. PLAXIS 2D software was used to analyze the slope protection schemes at low and high water levels incorporating the various supporting and reinforcing materials. Moreover, the PLAXIS 2D software was also utilized to predict the vertical deformations of improved flood control dikes with increased embankment height at different cases of flood water levels. In addition, the SLIDE software was used to predict the factor of safety by using limit equilibrium method for the various riverbank erosion protection structures. Furthermore. RESSA software was utilized to evaluate the slope stability of the erosion protection structures with geosynthetic reinforcements of Xedon riverbank in Pakse combined with gabions and mattresses. Laos PDR is mountainous with high elevations.
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    Mapping the Underground: Geotechnical Physical Properties Insights from Bengkulu City
    (2026-01-01)
    Mase, Lindung Zalbuin
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    Kamal, Thomas Mustafa
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    Putri, Melly Zuhadjar
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    Misliniyati, Rena
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    This study presents a three-dimensional engineering geology model of soil-layer physical parameters in Bengkulu City, Indonesia. The model provides an integrated understanding of the subsurface profile to support construction design and planning. Three-dimensional modelling is applied to identify subsurface geological layers and visualize key soil physical properties using colour-scaled parameter distributions. The analysed parameters include shear wave velocity, plasticity index, saturated unit weight, bulk unit weight, dry unit weight, water content, and degree of saturation. Data interpolation is performed using the Inverse Distance Weighting method, which is suitable for estimating parameter continuity within layers in 3D geological modelling. The resulting model identifies five generalised subsurface layers: sand, clay, soft rock, medium rock, and hard rock. Interpolated parameter variations are illustrated through geological profiles and Probability Density Function plots, enabling more straightforward interpretation of value distributions across the study area. Overall, the findings offer practical insights and essential baseline information for engineers and planners conducting soil investigations in Bengkulu City.
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    Utilization of ladle furnace slag from a steelwork for stabilization of soil cement
    (2022-10-25)
    Ayawanna, Jiratchaya
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    Kingnoi, Namthip
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    Sukchaisit, Ochakkraphat
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    Ladle furnace (LF) slag, waste from the steel-making process, was incorporated to improve the compressive strength of soil cement. LF slag was mixed to replace the cement in the soil-cement samples with wt% ratio 20:0, 15:5, and 10:10 of cement and slag, respectively. LF slag in the range of 5, 10, and 20 wt% was also separately added to the 20-wt% cement-treated soil samples. The soil-cement mixed LF slag samples were incubated in a plastic wrapping for 7, 14, and 28 days. The strength of soil cement was highly developed to be higher than the standard acceptable value (0.6 MPa) after incorporating slag into soil cement. The mixing of LF slag resulted in more hydration products for bonding soil particles, and hence improved the strength of soil cement. With the LF slag mixing either a replacement or additive materials in soil cement, the LF slag to cement ratio is considered to be less than 1, while the cement content should be more than 10 wt%. This is to promote a predominant effect of cement hydration by preventing the partially absorbed water on slag particles and keeping sufficient water content for the cement hydration in soil cement.
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    Effect of polymer and Portland cement on strengthen crushed rock for pavement base
    (2019-01-01) ;
    Bergado, D. T.
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    Ayawanna, J.
    The effect of concurrent use of liquid polymer and Portland cement as a reinforced material in crushed rock pavement base was investigated in this work. The strength of polymer-treated crushed rock (treated crushed rock) and ordinary crushed rock (untreated crushed rock) were characterized and compared. In strength analysis, the California bearing ratios (CBR) of untreated and treated crushed rock were determined under unsoaked and soaked conditions to simulate post-flood pavement damage. The unconfined compressive strength (UCS) was evaluated under unsoaked conditions for 2h, 1-day, 3-day, 7-day, and 28-day curing periods. The results showed that the CBR of untreated and treated crushed rock under soaked and unsoaked conditions were positively correlated with dry density. The CBR under the unsoaked condition of untreated crushed rock was identical to that of treated crushed rock. Meanwhile, under the soaked condition, the CBR of treated crushed rock was twice as higher than the untreated crushed rock. The swelling indices were 0% for both untreated and treated samples. The UCS of treated crushed rock showed positively correlation with the curing time. The use of liquid polymer and Portland cement, therefore, improved the strength of crushed rock pavement base in which effectively mitigate the post-flood pavement damage.
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    Microstructures within and outside the smear zones for soft clay improvement using PVD only, Vacuum-PVD, Thermo-PVD and Thermo-Vacuum-PVD
    (2020-12-01)
    Bergado, Dennes T.
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    Artidteang, Suthasinee
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    Nguyen, Trong Nghia
    Previous investigators have found increasing rates odf consolidation with increasing degrees of soft clay improvement using PVD only, Vacuum-PVD, Thermo-PVD and Thermo-Vacuum-PVD). This paper utilized scanning electron microscope (SEM) to evaluate and compare the microstructures of the clay specimens obtained from within the smear zone of both undisturbed and reconstituted samples in small consolidometer as well from within and outside the smear zone of reconstituted samples in large consolidometer. Before improvement, both reconstituted and undisturbed specimens showed anisotropic microstructures. In reconstituted specimen, face to face preferred orientations are revealed parallel to the horizontal plane. Meanwhile, in the undisturbed specimen, some degree of random edge to face mixed with face to face orientations were displayed. After improvement, the microstructures of Thermo-Vacuum-PVD revealed high levels of edge to face orientation in the vertically dominated smear zone, followed by Thermo-PVD, Vacuum-PVD, and PVD only. Moreover, the microstructures of specimens in the horizontally dominated outside of smear zone exhibited mainly face to face orientation and progressively mixed with edge to face orientation. The increasing intensities of edge to face microstructures were successfully correlated with increasing flow parameters and measured shear strengths corresponding to the increasing levels of improvement.
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    Compression load tests on bored and barrette piles founded in gravelly sediments
    (2021-04-01)
    Lin, San Shyan
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    Lai, Chia Hung
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    Chen, Wei Ning
    Compressive tests on piles socketed in gravelly sediments were conducted. Six bored piles and four barrette piles, with or without base grouting, were studied using back-analysis. A spline function was used to fit the measured data for pile load along the depth. Using the fitted spline function and assuming that behaviour at the pile-soil interface is hyperbolic, back-analysis was used to determine the model parameters by calibrating the design value of β (the product of the coefficient of horizontal soil stress and the value of the tangent of the effective angle of shearing resistance of the soil-shaft interface) and comparing the results of back-analysis and the measured data. The results of this comparison revealed that the results of back-analysis were sensitive to the measured data. A back-calculated β value that is, in general, larger than that found by current methods was obtained.
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    Evaluation of Interface Shear Strength Coefficient of Alternative Geogrid Made from Para Rubber Sheet
    (2023-04-01)
    Liangsunthonsit, Anubud
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    Jaroonrat, Pakkapon
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    Ayawanna, Jiratchaya
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    Naebpetch, Weerawut
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    In this work, elastic natural rubber compound sheet (RCS) and ribbed smoked sheet grade 3 (RSS) were studied as alternative replacements for polymer geogrid for soil reinforcement. In order to investigate the reinforcing effectiveness in three distinct environments using the interface shear strength coefficient (R<inf>in</inf>) by the large-scale direct shear test, the RSS and RCS geogrids were installed independently in sand, lateritic soil, and clay. Using either an RSS geogrid or RCS geogrid, the average R<inf>in</inf> is progressively smaller in reinforced sand, lateritic soil, and clay, respectively. Higher tensile strength of reinforced materials using the RCS geogrid than those using the RSS geogrid is encouraged by the better elastic characteristics of the RCS geogrid. Thus, utilizing the RCS geogrid-reinforced materials can better increase the shear strength of coarse-grained soil such as sand and gravel.