EVALUATION OF PARAMETERS AFFECTING HORIZONTAL STABILITY OF LANDING MATS
The parameters that affect the horizontal stability of airfield surfacing mats were studied by conducting a series of static full-scale buckling tests in the laboratory using various mats and lay patterns. AM2, XM18, and XM19 mats with simulated waterproofing were used in the testing. The mat test sections ranged from one to five panels wide with widths of up to 36 ft. It was found that the most predominant factor affecting the buckling load was the initial eccentricity characteristic of the mat system. Other factors were panel width, mat unit weight, and formation width. The magnitude of locking angle had no effect on the buckling load but did affect the profile of the buckled wave. The existence of resilient filler in the joints of the waterproofing mats reduced the locking angle but did not increase the buckling load. A series of buckling tests of madel AM2 mats of various widths were conducted in the laboratory; the mats were obtained from Utah State University. The results enabled the extrapolation of full-scale mat tests from short widths in the laboratory to airfield widths. Attempts were made to develop a mathematical model to compare with the buckling behavior of the prototype mats. It was found that the horizontal load at which buckling would be initiated depends almost exclusively on the vertical eccentricities existing in the mat at the time the load is applied; because of the random nature of initial irregularities in the real system, the initial buckling load is an unreliable measure of the load-carrying capacity of the system. Therefore, it was concluded that little benefit could be gained from more elaborate mathematical analyses directed toward a more exact determination of initial buckling load or of sustained postbuckling resistance. Analyses were thus made by a simplified articulated system composed of straight rigid bars and movement-free joints. Only qualitative comparisons between the idealized and real systems were made because (a) the joints of the real mat are not movement-free before locking, (b) there are shifts in the joints caused by horizontal load transfer through the joints during buckling. Methods by which the stability can be increased included several alternative lay patterns. These patterns, which enhance the postbuckling behavior and may increase the initial buckling load, are suggested and explained.
U.S. Army Waterways Experiment StationSoils and Pavement Laboratory
Vicksburg, MS United States 39180
- Chou, Y T
- Barker, W R
- Dawkins, W P
- Publication Date: 1976-9
- Features: Appendices; Figures; References; Tables;
- Pagination: 63 p.
- TRT Terms: Airport runways; Buckling; Landing; Stability (Mechanics); Test sections; Waterproofing materials
- Subject Areas: Highways; Pavements;
- Accession Number: 00142573
- Record Type: Publication
- Report/Paper Numbers: Tech. Rpt. S-76-10 Final Rpt.
- Files: TRIS, ATRI
- Created Date: Jan 16 1977 12:00AM