Simplified analysis for reflective overpressure on walls of rectangle-section tunnel due to its inner-explosion

Abstract

Based on the constructing thought of the displacement model of isoparametric finite element, an extended interpolating algorithm is deduced for calculating the overpressure history of an optional point on the walls of the rectangle-section tunnel under an optional point-explosion in its internal space. According to the working principle, the overpressure histories of all nodes on the walls of a tunnel with the equal width and height of 2 m, induced by a reference-charge explosion at each node in this tunnel’s cross section, are computed using the LS-DYNA software, and then are gathered to establish a reference database, which makes it possible to set optionally the positions of the explosive and the overpressure-observed point. In addition, some variation factors of peak values and durations of overpressure on the walls, reflecting some changes on the charge weight and the sizes of width and height of the section, are included in this algorithm in order to simulate approximately the overpressure responses on the walls under the optional charge weight and cross-section size. Some example analyses indicate the rapidity and validity of this method, and therefore this will bring it a good prospect in engineering application.

Keywords

rectangle-section tunnel / reference database / explosion overpressure / charge weight

References

[1] Smith P. D., Mays G. C., Rose T. A., et al. Small scale model of complex geometry for blast overpressure assessment[J]. International Journal of Impact Engineering, 1992, 123 345-360.

[2] Chan P. C., Klein H. H.. Study of blast effects inside an enclosure[J]. Journal of Fluids Engineering (Transactions of the ASME), 1994, 1163 450-455.

[3] Pritchard D. K., Freeman D. J., Guilbert P. W.. Prediction of explosion pressures in confined spaces[J]. Journal of Loss Prevention in the Process Industries, 1996, 93 205-215.

[4] Lee C. K. B.. Scaling blast-induced wall loadings in a rectangular room[J]. Pressure Vessels and Piping Division (Publication PVP), 1999, 394 45-54.

[5] Zyskowski A., Sochet I., Mavrot G., et al. Study of the explosion process in a small scale experiment-structural loading[J]. Journal of Loss Prevention in the Process Industries, 2004, 174 291-299.

[6] Yang X. M., Yang K. Z.. Explosion effects inside a confined space[J]. Chinese Civil Air Defence, 2006, 186(8): 64-64.

[7] Yang K. Z., Yang X. M.. Shock waves propagation inside tunnels[J]. Explosion and Shock Waves, 2003, 23(1): 37-40.

[8] Pang W. B., He X., Li M. S., et al. The formula for airblast time of arrival in tunnel[J]. Explosion and Shock Waves, 2003, 23(6): 573-576.

[9] Wang X. C., Shao M.. Fundamentals and Numerical Methods of Finite Element Method[M]. 1997 2 Beijing: Tsinghua University Press.

[10] Technical Manual (TM5-1300). Structures to Resist the Effects of Accidental Explosions [M]. Department of the Army, Navy and Airforce, Washington DC, USA, 1990.