Current Issue : January - March Volume : 2021 Issue Number : 1 Articles : 5 Articles
Successive earthquakes of Kocaeli and Duzce within three months indicated that even the survived lifeline structures such as\nbridges under the former event may have damage or collapse potential under the latter event due to their possible stiffness\ndegradation. It is thus important that a rigorous seismic analysis of such structures should account for the effect of prior\nearthquake damage. For this purpose, nonlinear seismic analysis of a reinforced concrete bridge structure has been carried out\nunder both single and multiple earthquake ground motions. Behavior and response evaluation of the bridge piers subjected to\nsuch motions have been discussed in terms of using both flexure-axial and flexure-shear-axial interaction models. Analytical\nresults show that the stiffness degradation under multiple earthquake ground motions is more pronounced than that under single\nearthquake ground motion. In addition, comparison of the response without and with shear demonstrates that shear deformation\nis of significance. The response with shear exhibits the increase in displacement demand and decrease in lateral force carrying\ncapacity, leading to a decrease in energy dissipation capacity. It is concluded that seismic analysis of reinforced concrete bridge\nstructure should account for the effect of multiple earthquake ground motions to assess the demand on such structure properly....
Environmental pollution problems and energy-saving issues of urban tunnels have increasingly been attracting peopleâ??s attention.\nThe paper aims at investigating a reasonable time factor for CO-based emission factors in the ventilation design of urban road\ntunnels........................................
This paper takes the cemented sand and gravel dam (CSGD) in Shoukoubao reservoir as the prototype to introduce in detail the\nsimilarity principle of model test and describe the selection steps of materials for CSG model. It has developed similar materials for\nCSGD model by mixing coarse sand, barite powder, gypsum powder, cement, and iron powder so as to provide reference for\nCSGD model test in the future. The dam model test has studied the stress distribution and displacement deformation of the dam\nduring construction and normal operation, in order to provide experimental support for the study of failure mechanism of the\nCSGD and facilitate the design and construction of dams of this kind....
The layout of houses and other buildings impacts the way in which foul sewer\npipework is positioned internally and externally. Less water to waste through\nconservation measures reduces the distance that gross solids transfer in sewers\nand increases the number of sewer blockages. Dwelling houses are often\nlaid out where the solids from faecal flushes are at the head of the sewer line\nwith other flows entering downstream. Discharges from appliances such as\nwashing machines, dishwashers, baths, showers and kitchen/utility sinks are\noften not utilised in the transfer of the gross solids when they enter downstream\nof the faecal flushes....
In the expressway reconstruction and expansion engineering, the form of rightward zone is increasingly adopted, and its\ncomplicated traffic conditions can easily cause traffic accidents. In order to quickly and effectively grasp the traffic risk of the right\ndiversion section, this study employs average speed, the coefficient of variation, the equivalent minimum safety distance, and the\ndeceleration as evaluation indexes of driving risk, and then analyses the influence rules of traffic volume, the proportion of large\nvehicles, and the length of the transition section on each evaluation index by using Vissim simulation software. On the basis of\nthis, we determine the weight of each evaluation index by the entropy method and establish the driving risk index evaluation\nmodel of the work zone with multiple linear regression....
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