Current Issue : October - December Volume : 2019 Issue Number : 4 Articles : 5 Articles
Field monitoring in the process of excavation of foundation pit is an important measure to reduce the risk. This paper describes a\ncase study of the filed monitoring data during the process of deep foundation pit excavation in soft soil areas. The displacements of\nthe diaphragm wall top were analysed and found that the horizontal displacement showed the convex shape, while the vertical\ndisplacement showed the concave shape. Based on the field monitoring data, the deformation mode of lateral displacement of the\ndiaphragm wall belonged to the composite mode. The relationship between maximum lateral displacement and excavation depth\nshowed a strong linear correlation. The horizontal displacements of bracing pillar decreased with the increasing of bracing\nstiffness, while the effect of bracing stiffness on vertical displacements of bracing pillar could be ignored. The settlement profile\ncomputed using the method of Hsieh and Ou was in good agreement with the field observations and better described the\ndevelopment trend of the ground surface settlement. The ratio of the maximum ground surface settlement....................
In order to evaluate the emergency evacuation capacity of subway stations,\nthe data collected were analyzed based on grounded theory, and an evaluation\nmodel of emergency evacuation capacity was constructed by combining the\nanalytic hierarchy process (AHP). Finally, 12 secondary indicators (categories)\nand 4 primary indicators (main categories) were obtained, among which\nthe primary indicators were management factors, emergency response, construction\nfactors and personnel factors. From the weight value calculated by\nanalytic hierarchy process, we can see that management factors and emergency\nresponse have great influence on the emergency evacuation capacity of\nsubway stations. Therefore, we should focus on management factors and\nemergency response to improve the emergency evacuation capacity of subway\nstations....
Offshore wind farm is a key item in green energy and sustainable development.\nThe Taiwan strait owns the world-class wind farm with average wind\nspeed of 12 m/s and a potential for 3000 hours/year of power generation.\nCompared to wind turbines on land, the offshore wind turbine provide more\nstable power and less obstacles as well as less power loss. The potential and\nadvantages of offshore wind farm development in the Taiwan strait has become\nthe aims of the Taiwan government policy from now to 2025. This research\nwill collect the historical climate data (wind and wave) of the Taiwan\noffshore wind farm in the Chan-hwa county. Combined the productivity loss\nrespected to the installation of wind turbine due to different wind speed effect,\nas well as the productivity loss respected to the construction of pile\nfoundation due to different wave height effect, this study will build up a total\nproject duration forecast system based on the historical climate data of the\noffshore wind farm. Even the literature views from the experienced projects\nin North Europe including UK, Netherland and Spain, the climate uncertainty\nstill plays a significant factor of the total construction duration for offshore\nwind farm. The results of this research can provide a more scientific and reliable\nduration forecast for future offshore wind farms construction in Taiwan....
Concrete creep has become one of the major problems that threatens concrete structural\ndevelopment and construction. However, a reasonable and accurate calculation model for\nnumerical analysis is the key to control and solve the creep deformation of concrete. To better\ndescribe the concrete nonlinear creep damage evolution rule, the visco-elasticity Plasticity\nRheological Theory, Riemann Liouville Theory and Combined Model Theory are quoted, and the\nAble dashpot is used to reconstruct fractional-order soft-body composite elements to propose the\nexpression of the stress-strain relationship of the elastomer, visco-elasticity plasticity body, and\nViscoplasticity body, considering the evolution of the concrete compression damage process. A\nnonlinear creep damage constitutive model of concrete, based on fractional calculus theory, is\nconducted, and the parameters of the specific calculation method of the model are given...................
Due to its high biocompatibility, bio-degradability, and low cost, cellulose finds application\nin disparate areas of research. Here we focus our attention on the potential applications of cellulose\nnanofiber in cement-based materials for the building sector. We first describe the chemical/morphological\ncomposition of cellulose fibers, their process and treatment, the characterization of cement-based\ncomposites, and their flexural strength. In recent research in this field, cellulose has been considered\nin the form of nano-sized particles, i.e., cellulose nanofibers (CNF) or cellulose nanocrystals (CNC).\nCNF and CNC are used for several reasons, including their mechanical and thermal properties, their\nextended surface area and lowtoxicity. This study presents some potential applications of lignocellulosic\nmicro/nanofibers (LCMNF) in cement-based composites in order to improve flexural strength. Samples\nwere made with 0.5-1.0-1.5-2.0 wt% of LCMNF obtained from pine sawdust, CEMI (Portland) and a 1:3\ncement-water ratio. The composites were then tested for flexural strength at 7, 14, and 28 days and\nthe evolution of flexural strength was assessed after water immersion during 72 h. Scanning electron\nmicroscopy was employed to visualize the bond between LCMNF and the cement matrix. Results\nshowed that LCMNF improved the flexural strength of the composite in all the dosages used....
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