ReSSA Software
ReSSA Software
- For a given problem (i.e., tiered slope/wall, different soil layers, complex layout of reinforcement, facing units, surcharge loadings, pullout interaction parameters, seismicity, seeping water, and user-specified rear-end reinforcement resistance) and a given target factor of safety, ReSSA+ calculates the maximum tensile resistance in the reinforcement, Tmax, its location, and the connection load, To, for each layer. This baseline solution provides a rational basis for selecting geosynthetic and facing considering long-term strengths values. The baseline solution defines the required reinforcement/connection load at any relevant location so as to produce a user-prescribed limit state. Note that the baseline solution is conducted using Bishops rotational failure considering failures emerging at the face and toe. Since other modes of failure, such as foundation or sliding instability, are possible, it is critically important to also assess global stability available in ReSSA+. However, this should be done after adequately selecting geosynthetic and connectors considering also the baseline solution.
- ReSSA+ enables visualization of the distribution of the required reinforcement resistance along each layer.
- ReSSA+ enables visualization of the location at which each Tmax is acting.
- ReSSA+ displays the Tension Map using a color-coded presentation to assess where reinforcement is hardly stressed or where it is overstressed. This diagnostic tool is critical towards optimizing the layout of the reinforcement system. See FHWA-HIF-17-004 or Leshchinsky et al. (2017).
- ReSSA+ allows for non-uniform reinforcement lengths. Such a feature is important if intermediate reinforcement layers are used. One can then include its impact on design, especially on connection loads.
- ReSSA+ enables visualization of the distribution of pullout resistance as calculated for both the connection and rear of the reinforcement.
- ReSSA+ presents tabulated numerical results for Tmax and To at each layer. The user can export this table to Excel.
- Upon switching to Global Stability mode in ReSSA+, the user can (and should) specify adequate reinforcement and connectors to ensure global stability considering various failure modes.
- Each dialog in ReSSA+ has its own extensive help.
- The user can specify up to 5 different types of interfaces for reinforcement for assessment of pullout resistance.
- In ReSSA+ live and/or dead surcharge loads can be considered. Also, impact of shear strength between stacked facing units can be explored in both Stage I and Stage II analysis.
- In the baseline mode (internal stability), the actual minimum factor of safety of front and rear pullout is calculated and presented graphically and numerically in a tabulated format. Unlike conventional analysis where this factor is a function of Tmax, in ReSSA+ it is a function of the computed distribution of load T(x) in the reinforcement.
- Horizontal displacement at the face of the slope can now be estimated in the baseline solution. This approximate displacement is based on simplified calculations resulting from the elongation (stretching) of each reinforcement layer considering its tensile modulus. This approximation is a consequence of the limit state methodology used to assess the reinforcement tensile load distribution in internal stability.