AN ANALYSIS AND DESIGN PROCEDURE FOR HIGHWAY-RAILROAD GRADE CROSSING FOUNDATIONS
Both highway and railroad organizations are concerned with the maintenance problems of highway-railroad grade crossings. The Texas State Department of Highways and Public Transportation spends approximately one-half million dollars yearly for the maintenance of grade crossings. It has been the usual experience of engineers and it is a conviction implicit in this study that a major portion of such maintenance costs may be reduced by an improved knowledge of actual behavior of a railroad track under both railway and highway traffic and the influence of environmental factors. Up to the present time, no rational approach to analysis and design of a grade crossing structure has been available. In this study a design system for a grade crossing is developed. A unique design criterion of permanent differential deformation between railroad track and adjacent highway pavements is established. This criterion is related to other existing criteria, available in pavement design literature, which are related to the rideability. Polynomial stress equations are developed separately for railroad and highway pavement under their typical design wheel loads to predict stresses at different depths. Characteristic properties of all materials involved, such as resilient modulus and permanent deformation under repeated loading are considered. The influence of environmental factors such as temperature and moisture balance on subgrade material characteristics is also included. A computer program is developed to calculate the differential deformation (the design criterion) for the purpose of the design of a grade crossing. The concept of differential deformation as a design criterion and the design system proposed in this report constitutes a new and rational approach to the design of highway and railroad grade crossings. Several example problems are presented to illustrate the whole design system. These examples also illustrate how these designs must change according to the variations in expected loading, temperature, climatic zone, and subgrade soil.
- Research sponsored by the Texas State Department of Highways and Public Transportation and performed in cooperation with the FHWA, U.S. DOT. See also RRIS 08 131327 7602, HRIS & RRIS 139714 (RRIS 08, 7702), HRIS & RRIS 145075 (RRIS 08; Bulletins 7702).
Arlington, TX United States 76011
Texas State Department of Highways & Public TranspP.O. Box 5051
Austin, TX United States 78763
Washington, DC United States 20590
- Ahmad, A
- Lytton, R L
- Olson, R M
- Publication Date: 1976-11
- Features: Appendices; Figures; References; Tables;
- Pagination: 104 p.
- TRT Terms: At grade intersections; Computer programs; Deformation; Design; Drainage; Environment; Highways; Maintenance management; Mathematical models; Pavements; Railroad grade crossings; Railroad tracks; Soil water; Stresses; Subgrade (Pavements); Subgrade materials; Traffic; Train track dynamics; Wheel loads
- Uncontrolled Terms: Design criteria; Maintenance costs
- Old TRIS Terms: Highway pavement; Track response investigations; Track structures
- Subject Areas: Design; Highways; Hydraulics and Hydrology; Operations and Traffic Management; Pavements; Railroads;
- Accession Number: 00157501
- Record Type: Publication
- Source Agency: Texas Transportation Institute
- Report/Paper Numbers: FHWATX77-1644F Final Rpt., TTI-2-18-74-164-4F, FCP 410-1042
- Contract Numbers: Study 2-18-74-164
- Files: TRIS, USDOT, STATEDOT
- Created Date: Aug 4 1977 12:00AM