Experimental study on the extant pre-stressed force to a 20-year old concrete simply-supported beam

<p>At present, Chinese high-speed railway operating mileage has exceeded 20 thousand km, and the proportion of the bridge is nearly 50%. Moreover, high-speed railway design speed is constantly improving. Therefore, controlling the deformation of the bridge structure strictly is particularly important to train speed-up as well as to ensure the smoothness of the line. This paper, based on the field test, shows the vertical and transverse absolute displacements of bridge structure by field collection. What’s more, resonance speed and dynamic coefficient of bridge were studied. The results show that: the horizontal and vertical stiffness of the bridge can meet the requirements of <b>Chinese “high-speed railway design specification” (HRDS)</b>, and the structure design can be optimized. However, the dynamic coefficient may be greater than the specification suggested value. And the simply supported beam with CRTSII ballastless track has second-order vertical resonance velocity 306km/h and third-order transverse resonance velocity 312km/h by test results, which are all coincide with the theoretical resonance velocity.</p>

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Large Deflections of a Simply Supported Beam Subjected to Moment at One End

Journal of Applied Mechanics ◽

10.1115/1.3167667 ◽

1984 ◽

Vol 51 (3) ◽

pp. 519-525 ◽

Cited By ~ 18

Author(s):

P. Seide

Keyword(s):

Linear Theory ◽

Bending Moment ◽

Critical Value ◽

The Other ◽

Large Deflections ◽

Simply Supported Beam ◽

Simply Supported ◽

Elastica Theory ◽

Angle Of Rotation

The large deflections of a simply supported beam, one end of which is free to move horizontally while the other is subjected to a moment, are investigated by means of inextensional elastica theory. The linear theory is found to be valid for relatively large angles of rotation of the loaded end. The beam becomes transitionally unstable, however, at a critical value of the bending moment parameter MIL/EI equal to 5.284. If the angle of rotation is controlled, the beam is found to become unstable when the rotation is 222.65 deg.

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The Natural Frequency Calculation Method of Simply-Supported Beam in the Sunshine Temperature Field

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.394.364 ◽

2013 ◽

Vol 394 ◽

pp. 364-367

Author(s):

Yong Chun Cheng ◽

Yu Ping Shi ◽

Guo Jin Tan

Keyword(s):

Temperature Field ◽

Calculation Method ◽

Natural Frequencies ◽

Bernoulli Model ◽

Simply Supported Beam ◽

Simply Supported ◽

Frequency Calculation ◽

Natural Frequency Calculation ◽

Beam Bridge ◽

T Beam

The related researches show that , the sunshine temperature field can cause the changes of the natural frequencies of the simply-supported beam. In order to recover the influence law of the temperature field on the natural frequencies, the calculation method of the natural frequencies of the simply-supported beam bridge is formed. First, according to the principles of stress equivalence, transform the sunshine temperature field to the partiality axis forces. Based on the Bernoulli model, the calculation method of the natural frequencies of the simply-supported beam under the partiality axis forces at both ends is formed. At last, take one simply-supported T beam as the object of numerical modeling and verify the validity and the reliability of this method.

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