The 2020 Burmister Lecture at Columbia University was delivered in April by Professor Dov Leshchinsky on Limit State Design Framework for Geosynthetic Reinforced Slopes and Walls.  This framework is acceptable for internal stability by AASHTO 2020 and was implemented in program ReSSA+. For the flyer announcing the lecture including its abstract click here.  Download the video of the presentation (220 MB), click here.  

In June 2018 ADAMA has released program ReSSA+. It includes special feature that enables to rationally determine the load along each reinforcement layer. The basis to this feature is presented in FHWA report FHWA-HIF-17-004. ReSSA+ has two useful diagnostic tools, the Tension Map and Safety Map, together enabling an efficient optimal use of geosynthetic reinforcement considering internal and global stability.ReSSA+ can seamlessly analyze geosynthetic reinforced slopes and walls, consider the impact of stacked facing units on internal stability and sliding stability, and assess the influence of deadman anchoring on internal stability. See more about ReSSA+!

Note that in recent updates of ReSSA+ (found here) the following features were added:

  1. In seismic Global Stability, 2-part wedge, the user can compute the yield acceleration at the elevation of each reinforcement layer. Using this acceleration, the user can follow given references to calculate approximated seismic displacements.
  2. 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.
  3. Horizontal displacement at the face of the slope can now be estimated based on the calculated distribution of reinforcement tensions. 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.

ReSSA+: Overview and Instructive Examples


NOTE: The posted Update 14 of MSEW includes an option to consider water in internal and external stability analyses. The methodology used corresponds to sudden drawdown of water next to waterfront structure.

Dov Leshchinsky, Ph.D., and Ora Leshchinsky, P.E., incorporated ADAMA Engineering in Delaware in 1989. ADAMA Engineering has been involved in geotechnical consulting to the public sector and has produced peer-reviewed and design-oriented public domain reports. Consulting to the private sector resulted in confidential reports, as requested by the client. ADAMA Engineering has offered numerous short courses on soil reinforcing and on slope stability engineering. ADAMA Engineering has provided expertise in forensic studies including litigation and review of designs.

The combined knowledge of geotechnical engineering and computer programming has enabled ADAMA Engineering to develop generic, useful software for practicing engineers. ADAMA Engineering has also developed customized software for the private industry and the US government. ADAMA Engineering software (programs MSEW, ReSSA, ReSlope, FoSSA and GeoCoPS, as well as its customized programs) has been used worldwide assisting qualified engineers in designing structures that are safe and economical.