Kinematical Element Method (KEM)

General information about the KEM

The Kinematic Element Method (KEM) is a software to investigate geotechnical limit load and stability problems based on limit equilibrium method.

The method is kinematically and statically correct, but requires a sufficient numerical optimization of the failure mechanism. The optimization goal is either the ultimate load or the reduction factor of the shear strength (Fellenius rule), defined as stability, at which the ultimate load disappears. The slip circle methods mentioned in DIN 4084 contain partly static errors and they are often not sufficiently adaptable, especially for non-homogeneous soils. With the KEM much more general failure mechanisms can be modeled.

The calculation procedure is briefly explained below using the example of the stability of a slope. The solid state continuum to be simulated is divided into several rigid elements (usually three to five or sometimes more). First the kinematic displacement and movement possibilities of the elements and then the equilibrium conditions are formulated. The existing safety factor against failure is obtained. The shape of the elements is varied until a minimum safety factor is found. This minimum safety factor then indicates the existing safety.

With the KEM, multiple layers and groundwater conditions as well as different external loads can be considered. Structural elements, e.g. gravity walls, can be included in the fracture mechanism. The load bearing capacity of anchors, nails or piles can also be recorded. The possibilities are illustrated by the examples given here.

The KEM Software was developed by Dr.-Ing. habil. Peter Gussmann and is maintained and further developed since 2011 in close cooperation with Mr. Gussmann from the Chair of Soil Mechanics, Foundation Engineering and Environmental Geotechnics at the Ruhr-University Bochum. The software runs on Windows 9x/ NT/ XP & Windows 7, 8, 10 platforms and is available as full version, demo version and student version.

Features

• Construction elements: any stratifications, water levels, surfaces and individual loads, anchors and nails
• Elements can be generated automatically or individually
• Optimization of the decisive geometry through powerful algorithms
• Visual control options and digital output of the results
• Graphical output of the varied KEM geometry, kinematics or force rectangle
• Each drawing can be saved and processed as an image file *.emf
• Toolbar, tooltips and menu displays in the status bar
• Demonstration of the application possibilities through more than 40 examples
• Optionally, the stability of a slope can be calculated according to the "Janbu" method
• Simulation of 3D effects via flank forces