Lateral Analysis

The results of lateral finite element analysis are output under the “Lateral Output” tab, in three formats:

  • The Full output - Single case provides the results of the lateral response analysis along the entire pile for a single load case. All available load cases are listed in the list box just above. The displayed load case can be changed by selecting a different load case in the list box.

  • The Lateral Summary tab presents a summary of the lateral analysis for all load cases at the selected grid point in the drop down list. By default, element “1” (the top element) is selected and the resulting summary can be interpreted as the pile head response. A summary at any other grid point can be generated by changing the selected grid element. The corresponding depth for each grid element can be found on the lateral Grid Table displayed on the Custom Input tab or in the Full output tabs.

  • The Full output - All cases displays the same as the “Full output - single case” tab and list all available load cases one below the other.

The standard output for a lateral analysis consists of:

  1. the grid point (i.e. the reference to the pile element number),

  2. the mid and bottom depth of the grid point,

  3. the shear load and bending moment in the grid point (following the sign convention displayed on the Load Cases tab),

  4. the lateral displacement and rotation,

  5. the soil resistance on the grid point,

  6. the bending stress in the pile,

  7. the number of iterations required and the lateral resistance ‘p’ normalised with the ultimate resistance for the grid point (i.e. showing the percentage of lateral resistance that is mobilised for that element).

Note that the maximum number of iterations to run is defined on the General tab, Analysis options. If no convergence is achieved after the specified number of iterations, OPILE will issue a convergence warning. Non-convergence may imply that either insufficient iterations were allowed and increasing the number will solve the convergence issue or the pile fails (i.e. the applied load is larger than the available resistance).

To generate a pile head response curve, use the Generate Load Lateral Load Cases button on the Load Cases tab. This will automatically create a set of load cases, assuming a fixed pile head (i.e. the rotation will be set to zero).

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Illustration of Full output for a single load case

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Illustration of the pile head response