1. |
- Settele, Josef, et al.
(author)
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Rice ecosystem services in South-east Asia
- 2018
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In: Paddy and Water Environment. - : Springer. - 1611-2490 .- 1611-2504. ; 16:2, s. 211-224
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Journal article (other academic/artistic)
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2. |
- Styrkarsdottir, Unnur, et al.
(author)
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GWAS of bone size yields twelve loci that also affect height, BMD, osteoarthritis or fractures
- 2019
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 10:1
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Journal article (peer-reviewed)abstract
- Bone area is one measure of bone size that is easily derived from dual-energy X-ray absorptiometry (DXA) scans. In a GWA study of DXA bone area of the hip and lumbar spine (N ≥ 28,954), we find thirteen independent association signals at twelve loci that replicate in samples of European and East Asian descent (N = 13,608 – 21,277). Eight DXA area loci associate with osteoarthritis, including rs143384 in GDF5 and a missense variant in COL11A1 (rs3753841). The strongest DXA area association is with rs11614913[T] in the microRNA MIR196A2 gene that associates with lumbar spine area (P = 2.3 × 10 −42 , β = −0.090) and confers risk of hip fracture (P = 1.0 × 10 −8 , OR = 1.11). We demonstrate that the risk allele is less efficient in repressing miR-196a-5p target genes. We also show that the DXA area measure contributes to the risk of hip fracture independent of bone density.
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5. |
- Do, Dao Huu, et al.
(author)
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Investigation of Performance of Soil-Cement Pile in Support of Foundation Systems for High-Rise Buildings
- 2018
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In: Civil Engineering Journal. - : Ital Publication. - 2476-3055. ; 4:2, s. 266-266
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Journal article (peer-reviewed)abstract
- This paper presents the experimental study of Soil-Cement Pile (SCpile) by wet mixing method in sandy soils, with the typical project at An Trung Complex apartment, Da Nang city, Vietnam. With the characteristic of soil layers is sandy soil, the strength of laboratory stabilized soils with the amount of cement from 150¸300 kg/m3 was determined. Simultaneously, the authors also performed the experiments of 20 test piles collected from the site which has cement content about 280 kg/m3 and the unconfined compressive strength qu= (4.5-6.0) MPa. After that, a full-scale model static axial compressive load tests of two single piles and a group of four piles with diameter 800 mm and 12 m length were also conducted. The experiment results show that the bearing capacity of every single pile is 1.200 kN with settlement 6.93 mm and the group of four CSpiles is 3.200 kN with settlement 5.03 mm. The results presented in the paper illustrate that SCpile is the suitable solution for foundation construction process with low cost and saving time for high rise buildings. The result shows a capable application of soil cement piles for support of high-rise buildings.
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6. |
- Guo, Xiangfeng, et al.
(author)
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Multi-objective optimization of geosynthetic-reinforced and pile-supported embankments
- 2023
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In: Acta Geotechnica. - : Springer Nature. - 1861-1125 .- 1861-1133. ; 18:7, s. 3783-3798
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Journal article (peer-reviewed)abstract
- The design of geosynthetic-reinforced and pile-supported (GRPS) embankments is traditionally optimized by searching for the most cost-effective solution among several workable candidates. The candidates are usually based on experiences of engineers, and the real optimal design could be therefore missed. This paper intends to address the above-mentioned issue by systematically optimizing the design of GRPS embankments considering simultaneously the cost and the safety in the entire design space. It is thus a multi-objective optimization (MOO) problem that differs from the studies only focusing on minimizing the construction cost. A practical MOO procedure is proposed in this paper, and it is applied to an illustrative GRPS embankment case. A set of nondominated optimal designs (Pareto front) are obtained at first, allowing an informed design decision. Then, four candidates located on the Pareto front are highlighted. Each of them represents an attractive design: the safest, the least-cost, the best trade-off (knee point) considering the two objectives, and the cheapest one for a target safety requirement. Finally, the optimal design can be selected from these four candidates depending on specific project purposes. For the case study, the knee point design leads to improvements in both the two defined objectives (i.e., decreased cost and increased safety) compared to the initial design, showing great benefits of performing a MOO analysis. By using the procedure, the optimal designs are also efficiently determined for the cases of different embankment heights.
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7. |
- Guo, Xiangfeng, et al.
(author)
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Probabilistic analysis of geosynthetic-reinforced and pile-supported embankments
- 2022
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In: Computers and geotechnics. - : Elsevier BV. - 0266-352X .- 1873-7633. ; 142, s. 104595-104595
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Journal article (peer-reviewed)abstract
- This paper presents a probabilistic analysis of a geosynthetics-reinforced and pile-supported (GRPS) embankment by using reliability, sensitivity and uncertainty propagation techniques. Compared to the traditional deterministic evaluation methods, the analyses performed in this work allow designers to rationally consider the uncertainties of material properties and quantify their influences on the embankment performance. Additionally, complementary information/results could be obtained which enables an informed design decision for engineers. This feature is further enhanced in the paper by proposing a new analysis procedure in which four carefully selected probabilistic techniques are combined with an efficient deterministic model. The contribution of the proposed procedure lies in providing a variety of valuable results (e.g., failure probability and sensitivity index) related to the GRPS embankment performance but with a limited computational time. An application of the procedure is presented in the paper. The obtained results revealed that the studied GRPS embankments have relatively low failure probabilities considering a usual traffic loading but could be risky under extreme loading conditions. Based on the sensitivity analysis, all the random parameters are ranked according to their quantified importance. Some discussions are also provided, trying to link the procedure with practical designs and to explain the uncertainty modeling with more details.
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8. |
- Pham, Tuan A., et al.
(author)
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3D numerical study of the performance of geosynthetic-reinforced and pile-supported embankments
- 2021
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In: Soils and Foundations. - : Elsevier BV. - 0038-0806 .- 2524-1788. ; 61:5, s. 1319-1342
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Journal article (peer-reviewed)abstract
- Geosynthetic-reinforced and pile-supported (GRPS) systems provide an economic and effective solution for embankments. The load transfer mechanisms are tridimensional ones and depend on the interaction between linked elements, such as piles, soil, and geosynthetics. This paper presents an extensive parametric study using three-dimensional numerical calculations for geosynthetic-reinforced and pile-supported embankments. The numerical analysis is conducted for both cohesive and non-cohesive embankment soils to emphasize the fill soil cohesion effect on the load and settlement efficacy of GRPS embankments. The influence of the embankment height, soft ground elastic modulus, improvement area ratio, geosynthetic tensile stiffness and fill soil properties are also investigated on the arching efficacy, GR membrane efficacy, differential settlement, geosynthetic tension, and settlement reduction performance. The numerical results indicated that the GRPS system shows a good performance for reducing the embankment settlements. The ratio of the embankment height to the pile spacing, subsoil stiffness, and fill soil properties are the most important design parameters to be considered in a GRPS design. The results also suggested that the fill soil cohesion strengthens the soil arching effect, and increases the loading efficacy. However, the soil arching mobilization is not necessarily at the peak state but could be reached at the critical state. Finally, the geosynthetic strains are not uniform along the geosynthetic, and the maximum geosynthetic strain occurs at the pile edge. The geosynthetic deformed shape is a curve that is closer to a circular shape than a parabolic one.
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9. |
- Pham, Tuan A., et al.
(author)
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A new index for the strength analysis and prediction of cement-mixed soils
- 2022
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In: European Journal of Environmental and Civil Engineering. - : Informa UK Limited. - 1964-8189 .- 2116-7214. ; 27:4, s. 1512-1534
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Journal article (peer-reviewed)abstract
- In geotechnical projects involving soft soils, cement-mixed soils are an excellent way to improve the mechanical behaviour and engineering performance of soils. The water-to-cement ratio, cement content, and porosity are the most critical parameters impacting the strength of cement-mixed soils, but their effects are less well understood. The proportional influence of cement amount, porosity, and moisture content on cement-mixed soil strength is investigated in this research. The results showed that as the water-to-cement ratio increases, the influence of cementation and porosity on unconfined compressive strength decreases. The blended volume ratio is proposed as a new and adequate index for evaluating cement-mixed soil strength based on the experimental results. The blended volume ratio is the product of the void/cement volume ratio and the water/cement volume ratio. While the current index has not fully addressed the important effects of the water-to-cement ratio and porosity, the blended volume ratio allows describing the concurrent influences of porosity, cement amount, and water amount on the strength development. The experimental results showed that the cement-mixed soil strength is a function of the blended volume ratio. An empirical equation based on the blended volume ratio was then proposed for predicting the strength of cement-mixed soils. The validation of the proposed equation is verified by strength analysis for several different test data sets. A good agreement between measured and predicted results indicated that the proposed model is applicable to predict well the strength of cement-mixed soils.
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10. |
- Pham, Tuan A., et al.
(author)
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A Simplified Method for Bearing-Capacity Analysis of Energy Piles Integrating Temperature-Dependent Model of Soil–Water Characteristic Curve
- 2023
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In: Journal of Geotechnical and Geoenvironmental Engineering. - : American Society of Civil Engineers (ASCE). - 1090-0241 .- 1943-5606. ; 149:9
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Journal article (peer-reviewed)abstract
- The bearing resistance of energy piles in the presence of temperature effects has not been thoroughly investigated, preventing the perfecting of energy pile design methods. Quantifying the relationship between soil suction and the temperature of unsaturated soils therefore becomes an important step in predicting the bearing resistance of energy piles. A new constitutive model based on interfacial energy and thermodynamic theories is therefore presented to predict the effect of temperature on soil suction as well as the soil–water characteristic curve (SWCC) in this paper. The analytical model for the nonisothermal matric suction was developed by combining five different temperature-dependent functions for the surface tension, air–water contact angle, void ratio, and thermal expansion of solid and water density, thereby providing a more complete approach than the one that considers surface tension only. The proposed formulation was expressed under a simplified form which is believed to be a useful and convenient tool to apply to a range of possible field situations. The temperature-dependent relationship of soil suction was then used to extend existing isothermal SWCCs to nonisothermal conditions that allow obtaining the SWCC at any temperature. The validity of the proposed model was verified by comparison to several test data sets for five different soils: swelling clay, hard clay, clayey–silty soil, ceramic material, and sand. The satisfactory agreement between predicted and measured curves proved that the proposed model had good performance in predicting the effect of temperature on the SWCCs of unsaturated soils. The nonisothermal SWCC model was then coupled with bearing resistance theory to produce a simplified method for analysis of energy piles. The results showed that the proposed method successfully predicted pile resistance at various temperatures when compared to experimental data. The pile resistance reduced as the temperature rose for a specific degree of saturation or if the soil was in an undrained condition. However, water evaporation may cause a decrease in water content and an increase in matric suction as the temperature increases. Therefore, as soils dry out, pile resistance may increase with increasing temperature.
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