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Geotechnical Engineering

 

Geotechnical Engineering - MSEW 1.0 Distribution Memo Attachment

MSEW Distribution Memo

General: Program MSEW follows the design guidelines for the design and analysis of Mechanically Stabilized Earth Walls as presented in FHWA's Demonstration Project 82 (DP 82) manual.

Operating System: MSEW is specifically designed to run on Windows 95, 98, and NT 4.0 operating system. It requires 15 MB of hard disk storage space. A SVGA display is needed.

Password: ADAMA Engineering, Inc., copyrights MSEW. The Offices of Technology Applications and Engineering, FHWA, are authorized to distribute MSEW 1.0 to U.S. Federal Agencies and U.S. State Highway Agencies. To enable controlled distribution, MSEW is password-protected.

Features:

  • MSEW can analyze walls reinforced with geogrids, geotextiles, wire mesh, or metal strips. It allows for reduction factors associated with polymeric reinforcement. Corrosion of metallic reinforcement can be assessed.
  • Up to five types of reinforcement can be specified for a single wall section. Strength, reduction factors (polymer), coverage ratio, and cross sectional area (metal) can characterize reinforcement 'type'.
  • MSEW has two modes of operation: Design and Analysis. In the Design mode, the program computes the required layout (length and vertical spacing) corresponding to user's prescribed safety factors. In the Analysis mode, MSEW computes the factors of safety corresponding to user's prescribed layout. In either mode, the program produces the 'ideal' reinforcement values for strength or coverage ratios so that the designer can maximize the utilization of reinforcement. That is, the ideal values can serve as guidance for a refined design.
  • The user can run MSEW first in its Design mode to obtain a 'computer-based' initial layout. This layout can correspond, for example, to the optimal vertical spacing of reinforcement layers, constrained by a prescribed feasible minimum and maximum spacing. Upon clicking on Analysis, all results obtained in Design are preserved as input data. The user can then modify the layout or properties of reinforcement layers to insure adaptation to local conditions.
  • Walls with facing batter of up to 20 degrees and with inclined backfill can be designed and analyzed. Tiered walls, trapezoidal walls, bridge abutment walls, and back-to-back walls can also be designed and analyzed.
  • MSEW considers uniform load (dead and live), strip footing, isolated footing, point load and horizontal load.
  • Seismicity can be invoked either in design (with specified safety factors that are different than the static ones) or in Analysis (producing both the static and seismic safety factors).
  • Different facing units, such as blocks (i.e., connection is based on friction), precast panels (similar to blocks but connection is mechanical), full height precast panels, or wrap-around can be specified. In the case of frictional connections, the connection strength is checked at all levels of reinforcement to assess the potential for reinforcement pullout or break; the confining pressure in between stacked blocks is estimated using the hinge height method. For mechanical connections the strength is evaluated for each layer.
  • Bearing capacity is calculated accounting for such factors as sloping soil at the toe or ground water table at the base. Ultimate bearing load and eccentricity are part of these calculations.
  • MSEW evaluates the mobilization of reinforcement strength and pullout at each elevation. It also calculates the mobilization of connection strength, resistance to direct sliding, and eccentricity at each layer.
  • The natural soil profile composed of up to five different soils, as well as the phreatic surface, can be input for global/compound (slope) stability computations.
  • Slope stability analysis (Bishop's method using circular slip surfaces) can be invoked to assess the potential for compound and deep-seated failures. The analysis automatically considers the reinforcement layout and available strength, including connection strength, the profile of the various soil layers, including retained and reinforced soils, the soil surface geometry, external loading, and seismicity. Re-runs of specific circles can be done at a click of a button. For judgement, the user can view each analyzed circle and its corresponding calculated driving and resisting moments, including the moment contribution of the reinforcement.
  • In case of unsatisfactory deep-seated stability, the user can specify basal reinforcement of sufficient length and strength. MSEW will produce the resultant factor of safety due to this basal reinforcement assuming a circular slip surface.
  • MSEW checks for conflicting input data.
  • Units can be SI or English.
  • The user can override default values to conduct instructive parametric studies or to allow for adaptation to unusual conditions.
  • MSEW Help is online. It includes all relevant chapters from the DP 82 manual. An additional chapter provides detailed information about the slope stability analysis. The user can print sections of the manual. Typing keywords allows the user to access information in Help. Some screens have their own help routines so that their usefulness can be realized quickly.
  • MSEW contains extensive graphics for both input and output data. Some of the graphics display force resultants, thus making evaluation of results easier. Other graphics provide instant visualization whether prescribed safety factors have been attained (green) or not (red).
  • Output data is in a tabular format. In Design, results specific to each stability mode can be viewed (intermediate results). This feature can be useful when assessing the synergy of all design criteria.
  • Results can be sent to printer as a report. Three different versions are available: abstract (2-3 pages); medium length (about 10 pages); and full report (15 to 20 pages). Selected pages can be printed individually.
  • Results can be saved as a text file. Most word-processors can retrieve such a file for editing and integration into the user's report.
  • Layout of reinforcement and slip circles can be captured as bitmap files. Most graphic programs and word-processors can retrieve these bitmap files allowing the user to modify and print it.
  • MSEW allows the user to retrieve and display up to four cross sections (bitmap files). This feature is handy for visual comparison of adjacent layouts. The user can capture these four layouts as a bitmap file.

REQUEST OF MSEW 1.0 PROGRAM

U.S. State DOT's and U.S. Federal Agencies only

All others interested in purchasing the MSEW software should contact ADAMA Engineering, Inc., at http://www.msew.com/

Contact:

 
Updated: 04/07/2011
 

FHWA
United States Department of Transportation - Federal Highway Administration