A full range of features which allow for the most general usage have been
incorporated into DASH/P. The basic capabilities of the system are
summarized in Table 1. Specific features apply to applicable specifications,
loadings, and structural configurations.
Specifications: Prestressed girder bridges are modeled, analyzed,
and code-checked in accordance with the latest AASHTO specifications.
Structural Configuration: A number of features are available in
DASH/P which allow analysis of various structural bridge configurations. A
summary of those features is given in Table 2. Further, since DASH/P is
matrix-based and modular, it is easily upgradable for incorporation of other
features.
Dead Load: The program is capable of automatically generating all
DL calculations in accordance with AASHTO for both composite and
non-composite construction stages. Specifications are:
- All dead load conditions are investigated automatically for various
construction stages;
- Special concentrated or uniform loads are available at the option of
the user;
- Prestressed tendon forces are converted automatically to equivalent
joint loads inside the computer program.
Live Loads: Incorporated with the DASH/P system is a most general
and wide range of live load capabilities with the utilization of influence
lines, as follows:
- Standard AASHTO truck and lane loadings;
- Interstate or military vehicles;
- Non-standard AASHTO loadings (HS-25);
- HL-93 for AASHTO LRFD Specifications;
- Generalized 20-axle (user-defined) arbitrary trucks;
- Application of all truck loadings in both directions;
- Impact factors for moments, shears, displacements, and reactions can
be defined by user; otherwise, they are computed internally in accordance
with AASHTO specifications;
- Distribution factors can be defined by user, or default to the AASHTO
Standard or LRFD specifications.
The methodology incorporated with the live load portion of DASH/P was
developed to be most generally applicable. Determination of all maxima is
accomplished by utilization of influence lines. The influence lines were
developed by placing unit loads at any user-defined point along the girder.
Limitations: DASH/P, developed with use of the most modern
programming techniques, has almost no size limitations. Program size can be
adjusted by changing only a couple of variables in the dynamic memory system
(only the sponsor of the program has the key to modify the size).
