Until recently, predicting the increase in soil resistance during pile driving due to short or lengthy delays was unfeasible. It has often relied on experience and judgement Estimating the hammer efficiency for theoretical wave equation studies was disputable. Dynamic measurements performed on piles during pile driving produced a wide varying range of unexplainable efficiency correlations From fifteen actual platform case studies comprising over eighty piles, design curves to estimate the average increase in unit friction and the ratio of average increase in unit skin friction to average unit adhesion at the resumption of pile driving as a function of time and depth are provided A new concept that explains the variation in dynamic measurement results is also provided A new theoretical method to construct the soil resistance during pile driving versus blows/foot curve is included It is hoped that the work included in this study will be an incentive for further research work / acase@tulane.edu

acase@tulane.edu

The transportation costs of low value per unit volume materials can become a major portion of the total distribution cost. A stochastic dynamic mixed-integer linear program of a transportation model containing intermediate processing stations between suppliers and demand centers has been developed which has been found to reduce total transportation costs by 39 percent over standard models. The model selects the optimal locations for the intermediate processing stations and the primary demand center from a given set of possible candidates. It includes costs of environmental constraints and includes the stochastic (e.g., seasonal) nature of the supply / acase@tulane.edu

acase@tulane.edu

A study on the static stresses developed by granular materials in storage containers is presented here in two parts. The first part of this work was initiated by the improvements provided by Cowin on the classical Janssen's formulas for bin static stresses. Janssen assumed that the horizontal and vertical stresses inside the bin at a particular depth were uniform. He also assumed that full frictional force is mobilized at the bin wall. Cowin replaced these stronger assumptions with less restrictive assumptions and rederived the essence of Janssen's results. In his improved formulas Cowin also included the effect of material consolidation upon the bin stresses, an aspect, which was not considered in the original Janssen's formulas. In the first part of this dissertation, a reassessment of most of the experimental investigation, based on Cowin's improved formulas is presented. Also, an experimental investigation on the granular material consolidation is reported and the results of this investigation show that the improved formulas are reasonable and practical In the second part, a concept from classical Janssen's theory is incorporated into an equilibrium continuum theory and applied to two dimensional bin and hopper problems. The method of characteristics is used to obtain the bin and hopper static stress solutions and the results are compared with solutions obtained from limiting static equilibrium (LSE) theory. The LSE theory also uses the method of characteristics and the solutions involve cumbersome numerical procedures. But, the method based on equilibrium continuum theory presents analytical solutions and gives bounds on bin and hopper static stresses / acase@tulane.edu

acase@tulane.edu

In the analysis of piles supporting offshore structures under lateral loading conditions, the key element is predicting the lateral load-deformation relationship (P-Y curves) for the soil. The present practice of constructing P-Y curves is based on the results of lateral load tests on instrumented piles and strength-deformation characteristics of the soil The research described in this paper was sponsored by Texaco U.S.A. It narrates a procedure for estimating the uncertainties in the computed deflections and bending moments in a pile subjected to lateral loads. In this procedure, the uncertainties in the soil properties and soil response are first estimated; then, employing the finite difference equations governing the pile behavior, estimates are made of the uncertainties in the computed curves which describe the lateral behavior of the pile The investigation utilizes three different computer programs: STRUDL, COM624, and BMCOL76. Since the present version of the INTRA program is not configured properly for the Texaco CDC computer, it is not included in this report Five example studies are presented in which an instrumented pile is embedded in different types of soil and subjected to static and cyclic loading. A study was carried out to compare the results from the three different computer programs to the instrumented pile test data Using the COM624 program results as the base case, the results from the other two programs are compared and evaluated Two special problems, mudslide and pile groups, are discussed based on an engineering approach / acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

acase@tulane.edu