%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  New template code for TAMU Theses and Dissertations starting Fall 2012.  
%  For more info about this template or the 
%  TAMU LaTeX User's Group, see http://www.howdy.me/.
%
%  Author: Wendy Lynn Turner 
%	 Version 1.0 
%  Last updated 8/5/2012
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%                           SECTION IV
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%



\chapter{\uppercase{Scientific Contributions}}
\section{Introduction}
\noindent In August 2012 this research was proposed, defended, and accepted by the research committee.  The proposed five scientific contributions of that are addressed are discussed herein
\section{Scientific Contributions}
\emph{Establish that bridge foundations possess a measurable IP response on known foundations at the control site.}
\noindent Each of the reinforced concrete foundations and steel H-piles show a measurable IP response in Chapter~\ref{chap:Experiment}.  After it is established that bridge foundations can be successfully imaged using ERI and IP the control site is used to determine and define the optimal testing method prior to experimentation on bridges.

\emph{Establish the range of applications for ERI and IP in the field to detect known foundations.}
\noindent Previous research has proved that ERI cannot successfully image long, slender piles like those tested in this study but that it can image foundations that are larger than 1 m, such as abutments.  ERI is included throughout this dissertation because the ERI model is used for calculating the goodness of fit for the IP model so it is an indicator of the quality of the IP data.  It is shown that IP can successfully image shallow foundations (1 m and less) as well as foundations up to 7.9 m that are 0.4--1 m in diameter.  The depth of the inversions shown herein are restricted by the available space available beneath bridges and the ERI/IP system at TAMU which is only capable of being 54 m long with 2 m spacing between electrodes.  Deeper investigations can be achieved with additional electrodes and cable sections.  If space is the limiting factor for the depth of investigation the post processing algorithm can still be used to provide a minimum depth of the foundation.  For scour analysis purposes, knowing that a foundation is at least 8 m deep is very useful information when dealing with a 1 m scour hole because engineers will know that the bridge does not need to be closed down immediately.  

It is shown that IP can successfully image reinforced concrete foundations and steel H-piles.  Concrete without reinforcement possess no measurable IP response and timber piles should be tested in future work.  Finally, it is possible to test in different soil types and through the presence of water.  Loose sands will greatly reduce the quality of the inversion resulting in a high RMS, but the post processing algorithm can still be used.

\emph{Develop a method to obtain the probability of non-exceedance of an unknown foundation depth with collected data from known foundations.}
\noindent A post processing algorithm is created and used as a quantitative estimation of the predicted foundation depths.  This data set and the known dimensions of the foundations are used to create a probability of non-exceedance curve to provide a confidence level of the depth estimates of truly unknown foundations.  The probability of non-exceedance is calculated for 13 cases and modeled using a lognormal distribution.  The lognormal curve fit to the data will be used to amplify or reduce the predicted depth of unknown foundations depending on the acceptable probability that the actual foundation is less than the depth predicted by IP. 

\emph{Evaluate the method for applications to other subsurface civil engineering infrastructure.}
\noindent ERI is successfully used to image an 11.43 cm galvanized steel gas line.  It is shown that by altering the angle of the array relative to the gas line that the size of the gas line can be reduced to more closely approximate the diameter of the pipe.  More testing of lines of varying diameter lines, varying depths, and in different soil conditions is still required to evaluate the full potential of ERI and IP for locating buried lines. 

\emph{Create acquisition protocols for using IP and ERI for unknown foundations to optimize its use nationwide.}
\noindent The acquisition protocol manual is included in the Appendix.  This manual discusses field set up of the equipment, how to process and post process the data, how to use to the established probability of non-exceedance curve, and includes a 'trouble shooting' section for common issues with data collection of bridge foundations. 