A purpose of this study is to simply evaluate pressure variation in stations having all covering roof. Round a running train, pressure field occurs. As this pressure field moves with the train, pressure variation is observed in the neighborhood of the passage train. We measured at stations having all covering roof to grasp the characteristic of the pressure variation. As a result, we confirmed that pressure variation at the time of train nose passage was bigger than the train tail passage, opening ratio had linear correlations with pressure coefficient maximum value in the specific station and when cross-sectional area of station became small the pressure variation grew big. In addition, we confirmed that the pressure variation was proportional to square of the train speed and we could apply the evaluation expression same as open area.
In the second place, by the measurement at opposite sides in stations having all covering roof, we tried to divide the pressure variation into one-dimensional component which is same in a section and three-dimensional component which depends on the distance from a train. As a result, we confirmed that we could divide into the both by confirmation of the waveform. And when we evaluated the pressure variation maximum value, we confirmed that one-dimensional component was dominant and the influence became small so that opening ratio became big. As we evaluated the pressure variation maximum value by the simple addition, we tried to construct the evaluation expression consisting of the addition of the one-dimensional component maximum value times α and three-dimensional component maximum value times β.
On the one-dimensional component maximum value, we confirmed that opening ratio had linear corrections with the pressure coefficient maximum value /R (2-R) of the one-dimensional component. We led an evaluation expression from the relations and confirmed that we could evaluate it with not depending on the train classification, an error of the 10 percent or so. We supposed that the three-dimensional component maximum value was inversely proportional to square of the distance from the train center, and we led an evaluation expression every train classification. We confirmed that the influence of opening ratio was small and we could evaluate it with an error of the 20 percent or so.
As a result, we suggested an evaluation expression of pressure variation maximum value in stations having all covering roof which is the addition of the one-dimensional component and three-dimensional component. And by the expression it was confirmed that we could predict the pressure variation of small sectional stations with 10 percent or so, and that of large sectional stations with 20 percent or so.
