نتایج جستجو برای: railroad bridge
تعداد نتایج: 54852 فیلتر نتایج به سال:
This paper proposes an ant colony optimization algorithm to assist railroad yard operational planning staff in their daily tasks. The proposed algorithm tries to minimize a multi-objective function that considers both fixed and variable transportation costs involved in moving railroad cars within the railroad yard area. This is accomplished by searching the best switch engine schedule for a giv...
T HROUGH an amendment to the Railroad Unemployment Insurance Act, approved by President Truman on July 31,1946, the Railroad Retirement Board was charged with the responsibility of establishing and administering a sickness insurance program for railroad employees.’ Thus, sickness benefits now form an integral part of the railroad retirement and unemployment insurance systems. The programs for p...
Abstract Bridges and viaducts are facing growing traffic, increasing loads as well ageing deterioration. Nowadays, vibration‐based Structural Health Monitoring (SHM) represents an effective solution to extract quantitative information regarding bridge structural condition. Bridge frequencies fundamental parameters capable reflect summarize dynamics health Typically, their identification is perf...
The feasibility of using railroad flatcars (RRFCs) as the superstructure for bridges on lowvolume roads has been investigated in two previous research projects at Iowa State University. The results of these projects verified that RRFCs are efficient and economical alternatives for low-volume road bridges. Two county engineers involved with the RRFC project cited cost as the main factor for choo...
Collapsible soils could widely be found in central part of Iran and has caused lots of problems for roads and railroads in that region. Appearance of wide cracks in the collapsible soil near the Tehran-Semnan railroad tracks has caused some worries regarding the safety and performance of the railroad. However, due to the high traffic of the railroad, it is impossible to block the road for remed...
Abstract The article is devoted to a study of the impact various environmental conditions on modal parameters, such as natural frequencies and damping ratios. analysis has been performed using Stochastic Subspace Identification (SSI) method measuring data every month same steel bridge structures located an important railroad route from Prague (the Czech Republic) Košice (Slovakia). structure ap...
The RRB administers comprehensive retirement/survivor and unemployment/sickness benefit programs for railroad workers and their families under the Railroad Retirement Act (RRA) and Railroad Unemployment Insurance Act (RUIA). These programs provide income protection to railroad workers and their families during old age and in the event of disability, death, temporary unemployment, or sickness. T...
Using modeling and simulation users can apply realistic interactions with their synthetic environments representing real world. In this study the synthetic environment is a hardware railroad model representing a miniature replica of a full-size railroad system under study. The hardware model is tested by means of real-time adaptive software simulator consisting of two subsystems: the virtual ra...
In the 1970's it was reported that there were approximately 2300 track miles of timber railroad bridges in the United States and Canada. For short spans, they offer an attractive alternative to other types of bridges as they are economical, faster to construct and easy to maintain. Current design practices do not allow an independent consideration of the effects of the dynamic loads in sizing o...
The participants in the grain logistics system need forecasts of railroad grain carloads. Although forecasting studies have been conducted for virtually every mode, no forecasting studies of quarterly railroad grain transportation have been published. The objectives of the paper are (1) specify a US quarterly railroad grain transportation forecasting model, and (2) empirically estimate the mode...
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