The VBA macro implemented in the enclosed spreadsheet calculates: (1) the time histories of velocity and displacement of the input acceleration time history, and (2) the spectral responses of acceleration (Sa), velocity (Sv), and displacement (Sd). The code is formulated based on the Newmark-bata numerical integration method. Note that C++ format of this code is… Read More
The enclosed spreadsheet uses a macro that is capable of estimating secant Young’s modulus at 50% of ultimate shear strength (), friction angle (), and undrained shear strength () of a soil layer based on typical borehole data such as SPT blow count and unit weight. This spreadsheet can be very handy when no CPT… Read More
Long-term consolidation, seismic dry sand and liquefaction-induced settlements of a soil deposit can impart significant amount of downward load to piles. This load, called downdrag or negative skin friction, is caused by the friction between the pile and the downward moving soil. In my previous post (click here), I explained how to calculate downdrag load… Read More
Long-term consolidation, seismic dry sand and liquefaction-induced settlements of a soil deposit can impart significant amount of downward load to piles. This load, called downdrag or negative skin friction, is caused by the friction between the pile and the downward moving soil. Per AASHTO LRFD Bridge Design guidelines, downdrag force should be determined as follows:… Read More
Sometimes you need to plot a graph that does not show data when a specific condition applies. For instance, in the process of liquefaction triggering analysis you may want to plot a graph that shows the variation of fines content for depths with Ic less than 2.6. You may try the options below without using… Read More
Approach of Boulanger and Idriss (2014) for liquefaction analysis requires performing iterations to determine and . In case you need to develop an excel spreadsheet that evaluates liquefaction based on Boulanger and Idriss (2014) approach, you may need to use the Macro below. Please note that based on my personal experience Excel’s built-in iteration module does… Read More